Modern four stokes?

[brp]

Whats the maintenance side of things like - time ? cost ?

Heard they high maintenance, what got me miffed as brother inlaw been on loads of trail rides
and to my knowledge never had the top off his 2005 YZF250F (be 300 plus hours easy) then others on trademe doing top end rebuilds as low as 70 hours

What gives ?

How many hours before a top end rebuild on your 250 or 450

How ofthen adjusting valves ?

Be looking at 2009 plus CRF450F if get one

[Boo]

It depends how there ridden, a trail rider may not have it bouncing of the rev limiter. Its just when they need a rebuild it costs more than the bike is worth.
09 CRF450 have a few problems which can be fixed with a after market parts.
They went to a 4 spring clutch. They really need an after market 6 clutch. They have an stink bug factor[ass up] they tell me a longer swing arm linkage improves it. It stalls at low speeds as the EFI is unable to monitor low RPM.
The clutch or ass up didn't improve in the later years, 2010-2012, don't know if they solved the EFI problem.

[motor_mayhem]

It depends how there ridden, a trail rider may not have it bouncing of the rev limiter. Its just when they need a rebuild it costs more than the bike is worth.
09 CRF450 have a few problems which can be fixed with a after market parts.
They went to a 4 spring clutch. They really need an after market 6 clutch. They have an stink bug factor[ass up] they tell me a longer swing arm linkage improves it. It stalls at low speeds as the EFI is unable to monitor low RPM.
The clutch or ass up didn't improve in the later years, 2010-2012, don't know if they solved the EFI problem.

I've got an 09 450 and love it. I didn't notice an ass up factor but then maybe my suspension is set to counter act that? Clutchwise I couldn't comment as mine feels like new because the previous owner renewed it before I bought it and I put a magura set up on it. The efi low revs thing did cause me to loop it on my first day out. On the plus side I like the narrow body, steering dampner is great and efi means really consistant starting.

A top end rebuild isn't actually too expensive and do-able by yourself with the right tools.

[ktm84mxc]

A modern 4 stroke will last a long time if the maintance is kept up eg check your valve clearances every 50 hrs, oil and filter change every 10 hrs, check/replace piston every 100 hours.
The problems start when they go bang eg dropped valve or blocked oil lines wrecking the head . As this is by far the most expensive part on the engine.

[brp]

Cheers guys

Yeah heard that about how they ridden but the bro inlaw no slouch and lends it to his 18 year old son for trail rides - maybe the yzf the one togo for ?

ktm84mxc - know the bro uses synthetic on a regular basis

[Boo]

It depends on what you gonna do with it and you. If your a light ass a 250 could be for you, the thing about a 250 vs a 450 is the 250 can be pushed harder due to its size. The problem with that is maintance can be higher. Where as a 450 you don't need to push as hard.
I persoanally think the last of the carby models are nice bikes in particular the YZF and CRF 450, don't know about the others but they could well be the same. The funny thing about the crf 450 the 09 crf 450 is the same price as the 07-08 on trade me.
The 09 will get cheaper because of the new model in 13

[brp]

Cheers Boo

(Read some good reviews on the 09 CR - voted bike of the year by respected crowds)


I'm 100kg, 98 on a good day :D

Do the 450's have much low down grunt like a big bore 2 stroke ? 400exc rode (about 2003 - 2004) it was all mainly up top - nothing then a big surge of power as the revs built - newer 450 similar power delivery ?

[Boo]

Standard no, but thats a good thing when trail riding, as it does'nt wear you out. At 100kg I would go to the 450 or though a 250 would be faster you would have to ring it, and may increase maintance costs. You would have to get the suspension revalved and the aftermarket clutch [it will go] at some stage on the 450.
A revalve would be anywhere between $500-$1100 with springs. Take it to a suspension guy, tell him what sort of riding you do, the good ones can use the same spring and just change the shims, gold valves are expensive, some say there good others say there not worth it. My experience with them is they are way more adjustable so as you improve and get use to the bike or faster you can adjust. Many justify money on making the bike more powerful and nothing on getting it to stop or handle better. Use oem fork seals they last longer.
Look for a STM slipper clutch for a 02-08 crf450, there are two versions dirt and motard either would be ok if your trail riding and are cheap secondhand, an aftermarket would set you back over $1100, you may need a basket with the STM .

[Boo]

Standard no, but thats a good thing when trail riding, as it does'nt wear you out. At 100kg I would go to the 450 or though a 250 would be faster you would have to ring it, and may increase maintance costs. You would have to get the suspension revalved and the aftermarket clutch [it will go] at some stage on the 450.
A revalve would be anywhere between $500-$1100 with springs. Take it to a suspension guy, tell him what sort of riding you do, the good ones can use the same spring and just change the shims, gold valves are expensive, some say there good others say there not worth it. My experience with them is they are way more adjustable so as you improve and get use to the bike or faster you can adjust. Many justify money on making the bike more powerful and nothing on getting it to stop or handle better.
Look for a STM slipper clutch for a 02-08 crf450, there are two versions dirt and motard either would be ok if your trail riding and are cheap secondhand, an aftermarket would set you back over $1100, you'll need a basket with the STM.

[brp]

How come the 250's can be pushed harder when there's only about 8 kg of difference in weight than a 450 ? (Suppose you on limit all the time so ya just twist the throttle fully open between corners too)

I was looking for something for local mx track ...

Cheers

[scott411]

How come the 250's can be pushed harder when there's only about 8 kg of difference in weight than a 450 ? (Suppose you on limit all the time so ya just twist the throttle fully open between corners too)

I was looking for something for local mx track ...

Cheers

its not so much the dry weight difference, its the rotating mass that makes a 450 feel heavy, bigger piston, crank clutch etc, makes it feel heavier as its harder to change direction,

[ktm84mxc]

for Joe average a 250F will be more enjoyable as you will be able to control the bike even when you get tired and start making mistakes, a modern 450F can take the unwary for a thrilling ride wether you want to or not. A 300cc kit on a 250F makes a good compromise between power and rider ability .

[brp]

Cheers guys - interesting points :niceone:

[motor_mayhem]

A 300cc kit on a 250F makes a good compromise between power and rider ability .

and largly reduces the selection of pistons and rings you can buy for it and would likely increase the wear on the rest of the engine (may run at reduced RPM but more torque applied to clutch/gearbox). If you want to go somewhere in the middle for weight and power I would suggest you look at a production middle bike like a 300 2T (KTM, GG or Husa) or a 350 4T KTM.

[Boo]

How come the 250's can be pushed harder when there's only about 8 kg of difference in weight than a 450 ? (Suppose you on limit all the time so ya just twist the throttle fully open between corners too)

I was looking for something for local mx track ...

Cheers
Yes its because your closer to the limit on a 450, usually in respect to speed and acceleration. Less time to react.

[Flicks]

A 450 has a taller engine too so the weight is alot higher in the bike. Which makes it feel heavier and harder to turn.

[brp]

Interesting stuff how larger crank and height etc makes noticeable difference ...


Yeah 300 2 stroke could be the go - with it firing twice as quick bit like having a 600cc four storke :msn-wink:


Cherz

[brp]

Good article

http://motocrossactionmag.com/mobile/News/YOU-ASKED-FOR-IT-MOTOCROSS-ACTIONS-TWOSTROKE-VERSU-7117.aspx

[Jinxycat]

and then after a while you can make one of these

https://www.facebook.com/photo.php?fbid=289408621165800&set=a.164739483632715.28729.164683603638303&type=1&theater

[Crisis management]

Good article

http://motocrossactionmag.com/mobile/News/YOU-ASKED-FOR-IT-MOTOCROSS-ACTIONS-TWOSTROKE-VERSU-7117.aspx

Made for an interesting read and pretty much accurate in my book. I'm at the stage of selling the 200exc and replacing it with a 450exc, simply because it's easier for me to ride the 4 stroke, easier to get up hills and I'm getting old & lazy. Quite correct about the slower turning 450, quite a noticeable difference in how you have to corner (don't ask for the solution yet, I haven't figured it out) as the 450 wants to stay up and going straight while the lighter bike is more flickable.
Depends on how you want to ride, I'm enjoying not having the 2 stoke "hit" but will miss the fast turning and I will see how I go in Riverhead (tight, steep and very slippery) before making a final comment.

[Boo]

I think you would really miss the 200 at Riverhead,you'll be working harder on the 450 due to its weight and handling.

[t595]

Made for an interesting read and pretty much accurate in my book. I'm at the stage of selling the 200exc and replacing it with a 450exc, simply because it's easier for me to ride the 4 stroke, easier to get up hills and I'm getting old & lazy. Quite correct about the slower turning 450, quite a noticeable difference in how you have to corner (don't ask for the solution yet, I haven't figured it out) as the 450 wants to stay up and going straight while the lighter bike is more flickable.
Depends on how you want to ride, I'm enjoying not having the 2 stoke "hit" but will miss the fast turning and I will see how I go in Riverhead (tight, steep and very slippery) before making a final comment.

Sounds like you need a 300. I've gone from 200 to 250 husaberg,completely different power. Like a tractor of the bottom with no real hit,still a heap of mid range and top tho

[Crisis management]

Sounds like you need a 300. I've gone from 200 to 250 husaberg,completely different power. Like a tractor of the bottom with no real hit,still a heap of mid range and top tho

Ridden a few 300s as well in my search for the perfect bike, and given unlimited funds would have taken a 390 Berg, however I'm happy with the 450 decision but am always open to buying something else if I'm proved wrong, Riverhead will be a proper test of my decision making!


As a sided note: where's the best place to buy race tech springs, local or direct from race tech? Being a skinny white guy I need springs that will let my 70kgs actually compress the suspension.... :shit:

[t595]

Ridden a few 300s as well in my search for the perfect bike, and given unlimited funds would have taken a 390 Berg, however I'm happy with the 450 decision but am always open to buying something else if I'm proved wrong, Riverhead will be a proper test of my decision making!


As a sided note: where's the best place to buy race tech springs, local or direct from race tech? Being a skinny white guy I need springs that will let my 70kgs actually compress the suspension.... :shit:

What rate?i have some spare sets. Or try slavensracing.com

[warewolf]

Even the 300EXC feels like a bus compared to the 200, but I reckon I'd take one over the 450 for its light weight if nothing else. The 300 feels lazy in its power delivery but it does get the power out. The 4Ts are all valve clatter and unless the throttle is already open and working, very sluggish to respond to the throttle. The extra grunt is more forgiving but they are much more tiring to weave between the trees. The 4T EXCs are nearly 20kg heavier than the 200, and have more reciprocating mass as well, whereas the 300 is only 2kg heavier.

[Crisis management]

What rate?i have some spare sets. Or try slavensracing.com

I'm after 4.0 or 4.2 kg/mm front springs (Racetech calculates 3.9kg/mm), don't know about the rear yet as I have to disassemble it first (and it feels better set up than the front which is very stiff)


Even the 300EXC feels like a bus compared to the 200, but I reckon I'd take one over the 450 for its light weight if nothing else. The 300 feels lazy in its power delivery but it does get the power out. The 4Ts are all valve clatter and unless the throttle is already open and working, very sluggish to respond to the throttle. The extra grunt is more forgiving but they are much more tiring to weave between the trees. The 4T EXCs are nearly 20kg heavier than the 200, and have more reciprocating mass as well, whereas the 300 is only 2kg heavier.

Hi Colin, I will give an honest report of my impressions from riding the 450 once I have done that (something about cracked ribs & sprained thumb from Buckets putting a brake on things ATM) but having ridden Andies 525 in the two man last year and a couple of other 450s' at Woodhill I think it's a do-able alternative for me.... old, slow & lazy! I promise to report back! Interestingly I found the 450 easier to ride in Woodhill (forestry & sand base) as i could loft the front more consistently and the added weight kept it more stable (less kicking out of the rear), turning was different tho and I think will take a bit more authority to achieve speed.. tree roots I will pass judgement on later, they are usually my downfall on the 200.

I weighted the 450 with half a tank of fuel and it's 117.6kg, I will weight the 200 when it returns (sons got it at the Sandpit today).

Edit: weighted the 200, full tank of fuel so 3 kgs in that.... 110.9kg.

Both weighted with the same scales so any error is the same the 450 is not so different after all! 10kgs!


Iain

[warewolf]

I had a look at the specs and over the years the 2Ts are getting heavier but the 4Ts are getting lighter! In 2003 it was 97 vs 115kg. At Woodhill I found that the 2T was lighter and more responsive, so it leapt up out of the sand easier and turned easier. And that was on a bike that had worse suspension than my 4T.

There is no black-and-white answer, just different shades of grey. When I'm using the grunt and solidness of the 4T, I want one...when I'm using the peppy zing of the 2T scalpel, I want one! :laugh:

[Pornstar]

So you're feelin the 200 is not enough these days aye?, so you crave some more useable power then aye? so you jump straight to a 450 4t? anyway enough of that, The answer is staring you in the face man, XC 250, Holy cow man, what a machine, I test rode one a few weeks back and would totally recomend you try one. Fantastic.

[Jay GTI]

the added weight kept it more stable (less kicking out of the rear.

Don't think that is necessarly due to the weight, more the way 4Ts are more effective at turning power into traction. My old RM would spit the rear out sideways in a heartbeat, which meant I'd pretty much have to be through the corner and upright before I put any real throttle in. With the KTM (weighs about the same as the RM), I can wind on a big handful of the throttle mid-corner, it just tends to dig in and and the power pulls the bike upright for me.

I lent the KTM to a guy with a 300EXC a couple of months ago at Woodhill and he was astounded at the difference in the corners. He was doing the same as the RM out of the corners, because getting on the gas too early on his 300 just kicked the back out, whereas he had been watching me power through corners on my bike and was surprised at how easy it was to do on the 4T.

The thing with the eternal 4T vs 2T arguement is that you can argue cost, power delivery, traction and all sorts of technical details until the cows come home, but rider preference is as much to play in it as any other factor. I do still miss the raw snot of my RM and the fact I could loft the front wheel over anything before my brain even registered I needed to, but I am ultimately a lot faster on the KTM. That is because the power is so much more smooth and controllable, I get way less arm pump and the KTM doesn't suddenly decide that it wants to kill me because I've looked at the throttle wrong, which was always an issue with the RM.

[flyingcr250]

Ridden a few 300s as well in my search for the perfect bike, and given unlimited funds would have taken a 390 Berg, however I'm happy with the 450 decision but am always open to buying something else if I'm proved wrong, Riverhead will be a proper test of my decision making!


As a sided note: where's the best place to buy race tech springs, local or direct from race tech? Being a skinny white guy I need springs that will let my 70kgs actually compress the suspension.... :shit:

Ive owned 5 ktm 300's, i ran my new 450xcf in at the last wmcc ride, it was the first time id really ridden a 450 before, i found it really good in the expert sections, and had no problems throwing it through the corners (after id gotten used to it), the torque is awesome something i feel the 350 lacks abit.

[Crisis management]

Thanks for all the feedback guys (and apologies for hijacking this thread), I'm a couple of weeks away from being allowed to ride it so will have to just polish the bloody thing and look at it in anticipation. Watch out for a 6 days upside down at Woodhill!

[brp]

Don't think that is necessarly due to the weight, more the way 4Ts are more effective at turning power into traction. My old RM would spit the rear out sideways in a heartbeat, which meant I'd pretty much have to be through the corner and upright before I put any real throttle in. With the KTM (weighs about the same as the RM), I can wind on a big handful of the throttle mid-corner, it just tends to dig in and and the power pulls the bike upright for me.

I lent the KTM to a guy with a 300EXC a couple of months ago at Woodhill and he was astounded at the difference in the corners. He was doing the same as the RM out of the corners, because getting on the gas too early on his 300 just kicked the back out, whereas he had been watching me power through corners on my bike and was surprised at how easy it was to do on the 4T.

The thing with the eternal 4T vs 2T arguement is that you can argue cost, power delivery, traction and all sorts of technical details until the cows come home, but rider preference is as much to play in it as any other factor. I do still miss the raw snot of my RM and the fact I could loft the front wheel over anything before my brain even registered I needed to, but I am ultimately a lot faster on the KTM. That is because the power is so much more smooth and controllable, I get way less arm pump and the KTM doesn't suddenly decide that it wants to kill me because I've looked at the throttle wrong, which was always an issue with the RM.

Reading the last paragraph ya old RM 2 stroker sounds like hell of a lot more fun ? It can be eternal the argument but 2 stroker getting fresh oil all the time (apart from the box of course) less moving parts, more powerful per cc with firing twice as quick, highly tune-able, lighter, cheaper to maintain and rebuild (DYI) - KaBoooM Factor - is hard to overlook - still doesn't stop me from being interested in a modern four stroke though :D

[ktm84mxc]

If you love a modern 4 banger buy one, if you love 2 smokes ride one ,it's all about choice.
some like the hit and scare\fun of a 2 smoke, or a 4 bangers power slides each to their own.
Me I prefer a smooth torquey ride with the hit a clutch flick away, compare a 2 smoke\4 banger by pushing them around a field or onto a trailer the weights may be close but the 2 smoke just feels lighter as the weights lower to the ground making it feel lighter.

[yokel]

For me pound for pound the 2 strokes has it over 4 strokes, The only way a 4 stroke gets one over a 2 stroke is in the power delivery and spread witch of cause is a big chunk of it for a lot of people, but for me the 4 stroke power makes me sleepy :baby:

2 strokes like the old (any) RM 250 were tuned to run against other 2 strokes not 4 strokes so people's ego for more power and fast revving seat of the paints speed takes over, you cant do this with a 4 stroke.

The things stopping me from ever getting a 4 stroke again is the weight, cost, engine braking, starting and the yuck handling ! like sex on a water bed on a boat on high seas going 40 knots

[Jay GTI]

Reading the last paragraph ya old RM 2 stroker sounds like hell of a lot more fun ? It can be eternal the argument but 2 stroker getting fresh oil all the time (apart from the box of course) less moving parts, more powerful per cc with firing twice as quick, highly tune-able, lighter, cheaper to maintain and rebuild (DYI) - KaBoooM Factor - is hard to overlook - still doesn't stop me from being interested in a modern four stroke though :D

Errrrr..... nope :D

There's elements to it I miss, but it was for the most part angry, cantankerous and hard to ride fast. I got used to it in the end, but spent the first 18 months of ownership scared of the bloody thing. A hell of a lot more fun for me is being able to consistently ride faster, for longer and without the bike biting me when I get it wrong (I get it wrong all the time). The RM put me in hospital twice, that about sums that bike up.

But that's the point I was badly making. You can give me any stat in the book, wave the running costs in my face all you like, I enjoy riding MX 4Ts more, because they suit my skills and riding style way more than a 2T.

[motor_mayhem]

For me pound for pound the 2 strokes has it over 4 strokes, The only way a 4 stroke gets one over a 2 stroke is in the power delivery and spread witch of cause is a big chunk of it for a lot of people, but for me the 4 stroke power makes me sleepy :baby:

2 strokes like the old (any) RM 250 were tuned to run against other 2 strokes not 4 strokes so people's ego for more power and fast revving seat of the paints speed takes over, you cant do this with a 4 stroke.

The things stopping me from ever getting a 4 stroke again is the weight, cost, engine braking, starting and the yuck handling ! like sex on a water bed on a boat on high seas going 40 knots

One man's meat is another man's poison.

The light switch effect of the 250 was plenty enough to put me off if I had somehow missed other riders spinning the wheels of their 2 strokes trying to get up hills or the handful who had managed to loop their bikes in bogs.
I don't think anyone would disagree with the cost factor but if it means I spend more time riding and less time pushing (which I find infinitely more tiring) then I am willing to spend the $$.

If you find four strokes boring, stop being so timid and wring the throttle a bit more, it's still an option on them, you just have to choose it rather than it being chosen for you.

In my mind sex on a water bed on a boat on high seas going 40 knots beats a lot of wrist action and sweating just to get your bike to climb 5 metres up a muddy hill

[warewolf]

If you find four strokes boring, stop being so timid and wring the throttle a bit more, it's still an option on themIt's not the wringing that's the problem, but the waiting. On my 2T, wring the throttle and sh!t happens. On the 4Ts, wring the throttle and it's wait, wait, wait, ok NOW we start making that smooth tractable power. There's no power when the throttle is cracked, just more valve clatter until it eventually revs up.:Pokey:

Light-switch effect of the 250? My 200 doesn't have a light-switch delivery and the 250s are supposed to be gruntier. :scratch:

I do think I'd be faster on a 250F, but I don't think it'd be funner.

[scott411]

For me pound for pound the 2 strokes has it over 4 strokes, The only way a 4 stroke gets one over a 2 stroke is in the power delivery and spread witch of cause is a big chunk of it for a lot of people, but for me the 4 stroke power makes me sleepy :baby:

2 strokes like the old (any) RM 250 were tuned to run against other 2 strokes not 4 strokes so people's ego for more power and fast revving seat of the paints speed takes over, you cant do this with a 4 stroke.

The things stopping me from ever getting a 4 stroke again is the weight, cost, engine braking, starting and the yuck handling ! like sex on a water bed on a boat on high seas going 40 knots

if you think a fuel injected 450 mxer is sleepy, your doing it wrong, the accellerate quicker than anything made out of corners,

i enjoy riding most stuff, = quick revving modern four strokes , 125's 250 2t's are fun to ride, but way slower around a MX track,

what most people said, its horses for courses,

[brp]

Errrrr..... nope :D

There's elements to it I miss, but it was for the most part angry, cantankerous and hard to ride fast. I got used to it in the end, but spent the first 18 months of ownership scared of the bloody thing. A hell of a lot more fun for me is being able to consistently ride faster, for longer and without the bike biting me when I get it wrong (I get it wrong all the time). The RM put me in hospital twice, that about sums that bike up.

But that's the point I was badly making. You can give me any stat in the book, wave the running costs in my face all you like, I enjoy riding MX 4Ts more, because they suit my skills and riding style way more than a 2T.

Guess the nope is for the RM personally not being as fun for you and not my points on the pluses for two strokes ?

1990 KX 500 - 65 HP Rear Wheel Horsepower and weighs 99 KG's - how many modern four strokes have those stats and its a 22 YEAR OLD bike - "Yeah yeah there's this modern four stroke model that puts out 67 HP" well there should be its 22 years later but less than 22 years later there's guys over in the states where 85 Rear Wheel HP on their old 22 year old bikes is common place and didn't have to take out a 2nd mortgage to do so.

2 stroke slower round an MX track ? - And thats why they stopped 2 strokes from racing against 4 strokes - bit hard to start marketing modern four strokes so the spare parts side of the business can be the real golden cash cow when 2 strokes are whipping your ass. As for a two stroke having no poke up hill - not a problem for a dirty 5.

Put likes of Shane King in his day on a 2 stroke and no doubt he would be much quicker round the track than if he were on a four stoke. Its only the crème de la crème that can ride a 2 stroke at the max - many years in the saddle.

[scott411]

Guess the nope is for the RM personally not being as fun for you and not my points on the pluses for two strokes ?

1990 KX 500 - 65 HP Rear Wheel Horsepower and weighs 99 KG's - how many modern four strokes have those stats and its a 22 YEAR OLD bike - "Yeah yeah there's this modern four stroke model that puts out 67 HP" well there should be its 22 years later but less than 22 years later there's guys over in the states where 85 Rear Wheel HP on their old 22 year old bikes is common place and didn't have to take out a 2nd mortgage to do so.

2 stroke slower round an MX track ? - And thats why they stopped 2 strokes from racing against 4 strokes - bit hard to start marketing modern four strokes so the spare parts side of the business can be the real golden cash cow when 2 strokes are whipping your ass. As for a two stroke having no poke up hill - not a problem for a dirty 5.

Put likes of Shane King in his day on a 2 stroke and no doubt he would be much quicker round the track than if he were on a four stoke. Its only the crème de la crème that can ride a 2 stroke at the max - many years in the saddle.



having raced, and won on a KX500, they are not as fast around a MX track as a 450, and putting them in a modern frame does not change it, the rules were screwed up which allowed the 250F's in with the 125, but in NZ (since 07) and Aussie you can race like for like on cc's and 4 strokes still dominate the top 10's,

Shayne King was the last winner of the 500cc class on a 2 stroke, and he changed to a 4 stroke the year after

you are right, a 500cc 2 stroke is the fastest thing in a straight line, motocross tracks are more than straights tho,

and KX500 were even more hp in 1986 than they were in 1990, but they had to make them more rideable, Horsepower does not win MX races,

[Jay GTI]

Guess the nope is for the RM personally not being as fun for you and not my points on the pluses for two strokes ?



Yeah, my point. For me, no the RM was not more fun, but it sounds like it ticks all your boxes. So I like 4Ts, you like 2Ts, personal preference.

I was waiting for the stats arguement to start in this thread though. As Scott says, horsepower does not win races, so it's academic to quote peak output power and say that it is proof a 2T is faster than a 4T around an MX track.

The last few years have seen some of the manufacturers put a lot of effort into taming 450s, because all but the top guys were finding them too hard to ride. More effort was spent on making the power usable, rather than chasing the peak HP figure. Not to mention I've read numerous articles from MX engine builders for the factory and pro teams saying they generally don't try and increase power on the big spec 450s, just work on power delivery. 85hp is not going to make you faster.

DK has also said that his 250 2T, which he races against 250 4Ts in his class, is definitely slower than the 4Ts around some tracks, but he wins because he has the experience and race craft that the younger guys don't have. So he wins, not the bike.

I always like to post this vid of a reasonably well ridden 250 2T, the comments at the end pretty much sum it all up:

http://www.youtube.com/watch?v=6nmmh67R6_E&feature=related

But at the end of the day, this is all pointless really. If you like 2Ts, buy a 2T, if you're like me and prefere 4Ts, buy one of them instead.

[eelracing]

DK has also said that his 250 2T, which he races against 250 4Ts in his class, is definitely slower than the 4Ts around some tracks, but he wins because he has the experience and race craft that the younger guys don't have. So he wins, not the bike.

Haha,peel away the bullshit and you're left with the fact that you don't send a boy out to do a mans job.DK is no dummy...but he thinks some of you are.

I always like to post this vid of a reasonably well ridden 250 2T, the comments at the end pretty much sum it all up:

Reasonably??? jesus that was awesome,and if 250 2T's were allowed to compete against 250 4 strokes in the AMA he'd be the first to swap over.
The comment "if you get passed by one of these things and your on a 450,you should quit" sums it up nicely.

But at the end of the day, this is all pointless really. If you like 2Ts, buy a 2T, if you're like me and prefere 4Ts, buy one of them instead.

I don't agree at all,a 2T is by far and wide the best application for offroad riding and racing...lightweight,instant snap,and cheap and simple to work on for the common man.You just have to choose your CC realistically to your riding ability,not your ego.
If 2 Strokes had the same developmant as 4 $trokes over the last ten years,chassis wise and FI/DI wise,we would'nt be having this conversation.

[Jay GTI]

I don't agree at all,a 2T is by far and wide the best application for offroad riding and racing...lightweight,instant snap,and cheap and simple to work on for the common man.You just have to choose your CC realistically to your riding ability,not your ego.
If 2 Strokes had the same developmant as 4 $trokes over the last ten years,chassis wise and FI/DI wise,we would'nt be having this conversation.

Good for you, you prefer 2Ts. I don't.

And the "if 2Ts had the same development..." arguement doesn't stack up. They have, the main Euro manufacturers have all spent plenty developing their 2Ts, KTM have been working on FI/DI for ages and Ossa have made it a reality. We should also be seeing the return of Maico next year, which will produce 2Ts only, designed in conjunction with a F1 team. It's only the Japanese that turned their backs on 2T.

[motor_mayhem]

Guess the nope is for the RM personally not being as fun for you and not my points on the pluses for two strokes ?

1990 KX 500 - 65 HP Rear Wheel Horsepower and weighs 99 KG's - how many modern four strokes have those stats and its a 22 YEAR OLD bike - "Yeah yeah there's this modern four stroke model that puts out 67 HP" well there should be its 22 years later but less than 22 years later there's guys over in the states where 85 Rear Wheel HP on their old 22 year old bikes is common place and didn't have to take out a 2nd mortgage to do so.

2 stroke slower round an MX track ? - And thats why they stopped 2 strokes from racing against 4 strokes - bit hard to start marketing modern four strokes so the spare parts side of the business can be the real golden cash cow when 2 strokes are whipping your ass. As for a two stroke having no poke up hill - not a problem for a dirty 5.

Put likes of Shane King in his day on a 2 stroke and no doubt he would be much quicker round the track than if he were on a four stoke. Its only the crème de la crème that can ride a 2 stroke at the max - many years in the saddle.


I don't agree at all,a 2T is by far and wide the best application for offroad riding and racing...lightweight,instant snap,and cheap and simple to work on for the common man.You just have to choose your CC realistically to your riding ability,not your ego.
If 2 Strokes had the same developmant as 4 $trokes over the last ten years,chassis wise and FI/DI wise,we would'nt be having this conversation.

1. Modern four stroke bikes are more plentiful so to get one versus a modern two stroke is actually cheaper.

2. Four strokes have experienced more development in the 200X decade. However they had a fair bit to catch up considering the previously existing four strokes (XRs,DRs,TTs,KLXs) experienced very little if not no engine development in the 199X and 198X years. Maybe not for Yamaha, but for KTM, GG etc chassis development in one type actually benefits all round - 2012+ 125sx's now have the linkage that was "tested" on the 2011 350sxf

3. Why do 2T fanatics constantly bitch that they must go cc for cc to help prove their bike is better? If the weight difference (rotating and stationary) that you crap on about so much is so important why is it still not enough to beat a 450 4T? And depite that "huge" weight and power advantage you have over 250 4T why did MXA's comparison say you will do your fastest AND slowest laps on the yz250 when against yz250f?

4. The instant snap you refer to on the 2T is the biggest reason the 4T's are better. The control of the power means that you can realistically have much more power than you need and not have to worry about accidentally tapping into it.

5. What authority decided that the 2T powerband is the only way fun can be had on a bike? Personally I find winning to be fun particularly if it's only one of your mates who you will get to exchange banter with afterwards (which is really the only winning I do). And I do more of that winning on a 4T.

FTR I am not opposed to 2T's at all and I am more than happy to acknowledge that there are some indisputable advantages (I'm actually looking at one, probably 125, to add to my garage as I think their strengths and weaknesses are virtually opposite to my current machine). But I get sick of some of the ridiculously biased and unbalanced dribble that gets written in the name of bettering the 2T cause.

[bogan]

If 2 Strokes had the same developmant as 4 $trokes over the last ten years,chassis wise and FI/DI wise,we would'nt be having this conversation.

Take a look at the skidoo FI/DI tech, there has been a lot of development there. It hasn't made it to MX because DI is far more suited to slow to rev engines at the moment. It obviously isn't an easy job to get em to rev quicker. Most chassis development would be easily transferable if the engines were competitive.

Don't get me wrong, I think 2Ts are at least as fun to ride as 4Ts, but they aren't as quick.

[Brian d marge]

having raced, and won on a KX500, they are not as fast around a MX track as a 450, and putting them in a modern frame does not change it, the rules were screwed up which allowed the 250F's in with the 125, but in NZ (since 07) and Aussie you can race like for like on cc's and 4 strokes still dominate the top 10's,

Shayne King was the last winner of the 500cc class on a 2 stroke, and he changed to a 4 stroke the year after

you are right, a 500cc 2 stroke is the fastest thing in a straight line, motocross tracks are more than straights tho,

and KX500 were even more hp in 1986 than they were in 1990, but they had to make them more rideable, Horsepower does not win MX races,

I think its how the traction is put down , 4t every 720 , 2t every 360 , everytime I raced againt a four , it came out of the corners better ...
Stephen

[t595]

I don't agree at all,a 2T is by far and wide the best application for offroad riding and racing...lightweight,instant snap,and cheap and simple to work on for the common man.You just have to choose your CC realistically to your riding ability,not your ego.
If 2 Strokes had the same developmant as 4 $trokes over the last ten years,chassis wise and FI/DI wise,we would'nt be having this conversation.

Think you might be right, out of 690 bikes a 2t won the 2012 isde....maybe they can get up muddy hills after all :killingme

[brp]

Shane King probably went to 450's cause that's what his sponsors wanted - "This bike faster than that bike" what bike a rider most comfortable on a big factor, 500 open class 2 stroker finished - probably cause were selling bugger all parts cause they just keep going and going - Don't under estimate how much of a factor the spare parts business is to the major 3 jap companies .....

Big point from the James Stewart video I picked up on is when he said how much fun these things are ...

Each to their own - I like both configurations - just think the 2 stroke gets an un-warranted bad rap by some - when if the real guide of the laws of physics is brought in - the 2 stroker is way ahead in the main.

[green machine]

Shane King probably went to 450's cause that's what his sponsors wanted - "This bike faster than that bike" what bike a rider most comfortable on a big factor, 500 open class 2 stroker finished - probably cause were selling bugger all parts cause they just keep going and going - Don't under estimate how much of a factor the spare parts business is to the major 3 jap companies .....

Big point from the James Stewart video I picked up on is when he said how much fun these things are ...

Each to their own - I like both configurations - just think the 2 stroke gets an un-warranted bad rap by some - when if the real guide of the laws of physics is brought in - the 2 stroker is way ahead in the main.

http://www.youtube.com/watch?v=6nmmh67R6_E&feature=related
Is this the vid....interesting comments he had at the end about sounding like he was going really fast but in reality he wasn't,

[brp]

What bike does Stewart normally ride a 2 or a 4 stroke ?????????????????? Hardly going to give a 2 stroke a glowing report is he ? Do ya think his sponsors would love him to do so ?

Going slow - did the thing look like it was going slow ?


Cheers

[brp]

having raced, and won on a KX500, they are not as fast around a MX track as a 450, and putting them in a modern frame does not change it, the rules were screwed up which allowed the 250F's in with the 125, but in NZ (since 07) and Aussie you can race like for like on cc's and 4 strokes still dominate the top 10's,

Shayne King was the last winner of the 500cc class on a 2 stroke, and he changed to a 4 stroke the year after

you are right, a 500cc 2 stroke is the fastest thing in a straight line, motocross tracks are more than straights tho,

and KX500 were even more hp in 1986 than they were in 1990, but they had to make them more rideable, Horsepower does not win MX races,

Yah got result times for both seasons for Shane King ?

Cheers

[green machine]

What bike does Stewart normally ride a 2 or a 4 stroke ?????????????????? Hardly going to give a 2 stroke a glowing report is he ? Do ya think his sponsors would love him to do so ?

Going slow - did the thing look like it was going slow ?


Cheers
He races 4 strokes now,tho he cut his teeth on a 125,Yamaha was what he rode at the time that vid came out,to me it looked fast as f**k
.....going slow is what he said,not me...and i'm sure he'd have a fair idea.....for the record i have no bias either way,we all ride what we like

[Boo]

I've seen that Steward video I think. Riding a YZ250, I thought he needed to change up another gear. Reving the guts out of it, if he had changed up another gear he would of really had to be on his game.

[brp]

Agree Boo !

True green machine !

The 2 vs 4 stroke all based on opinion- like guys signature on here - opinions are like assholes everybody has one ......

Cheers all for the "Heads up" on mod four strokes

Just get out and ride !

[yokel]

Yeah It's funny when people think their opinions are in deed facts.

On that note, this is why 4 strokes are awesome.

http://www.kiwibiker.co.nz/forums/showthread.php/153728-2003-yz250f-noise-after-drowning.

[flyingcr250]

modern 2t are awesome, modern 4t are awesome too, but when youre having problems with either one, they quickly become a piece of shit that you wish youd never bought. after my 2011 ktm 350 blew up ( http://www.kiwibiker.co.nz/forums/showthread.php/148725-When-good-bikes-go-bad ) i swore off 4 strokes forever, a few months and a couple of 2 strokes later and......

<img src="http://imageshack.us/a/img692/6964/28112647166029556307019.jpg" alt="Image Hosted by ImageShack.us"/><br/>

[Jay GTI]

modern 2t are awesome, modern 4t are awesome too, but when youre having problems with either one, they quickly become a piece of shit that you wish youd never bought. after my 2011 ktm 350 blew up ( http://www.kiwibiker.co.nz/forums/showthread.php/148725-When-good-bikes-go-bad ) i swore off 4 strokes forever, a few months and a couple of 2 strokes later and......



A couple of 2Ts? I know you went 300exc again after the 350, but what was the other one?

[pete.ktm]

a few months and a couple of 2 strokes later and...... 450 XC-F


rode the XC-F range at the KTM demo day, awesome bikes!

got home and downloaded the manual, suggested piston replacement @ 50 hours :(

compared to 350EXC-F suggested replacement @ 100 hours.

compared to my 450exc riden pretty easy on trail rides not needing work till 300 hours.

you reckon they're just being over cautious and thats racing hours? the shop mention they're a bit more maintenance than the exc range?

cheers

[Boo]

Geeze, the manufactures have got it sussed, when it blows up like flyingcr250, 350 and they don't know why?????.
Suppose if they said it loaded itself onto the truck and made you a coffee, you would tell them you wanted it with milk and five sugars.

[Jay GTI]

rode the XC-F range at the KTM demo day, awesome bikes!

got home and downloaded the manual, suggested piston replacement @ 50 hours :(

compared to 350EXC-F suggested replacement @ 100 hours.

compared to my 450exc riden pretty easy on trail rides not needing work till 300 hours.

you reckon they're just being over cautious and thats racing hours? the shop mention they're a bit more maintenance than the exc range?

cheers

That'll be racing hours, my SX-F (same engine as the XF-F) 99% trail riden and doesn't get anywhere near the abuse it would if I was a fast MX rider.

...and unlike FlyingCR's one, mine still runs sweet nearly 2 years after I took delivery. Even fired up off the button after it had been sat unmoved in my garage for 2 1/2 months.