450 MXer Pitfalls?

[Coyote]

I'm looking at getting a 450 Motocrosser over the next 6 months once I've sold my CBR, prefurably a WR450. What I wanted to find out first is what are the problems with owning a 450 4 stroke? How often will I be looking at rebuliding it and at what cost? Could I learn to work on the engine myself and rebulid it or would it be too advanced for a inexperienced kid like me to work on?

[Badcat]

I'm looking at getting a 450 Motocrosser over the next 6 months once I've sold my CBR, prefurably a WR450. What I wanted to find out first is what are the problems with owning a 450 4 stroke? How often will I be looking at rebuliding it and at what cost? Could I learn to work on the engine myself and rebulid it or would it be too advanced for a inexperienced kid like me to work on?

that looks like a ron wood flat tracker - very similar to what i'm building...
are you thinking of building a WR 450 into a street tracker?
if so i can forward you some examples - PM me.

ken

[Motu]

From what I've heard the Yamaha is the most sorted of the modern 4 strokes,but they are still big on maintanence - lots of oil changes using expensive oil,and regular top end rebuilds....depending on use of course.The modern 2 stroke needs less maintenance than the modern 4 stroke these day,and cheaper too.

[cowpoos]

as motu said....or get a kawasaki KLX300r...light weight [105kgs i think?] 34hp...and shit they have a good chassis....
and they don't have the maintainance of the majority of mordern MXer's...I use mine daily...it gets a service every 3-4thou k...or 2mnths [i usually about the 3.5k-3.7thou every 2 mnths] I abuse the shiut of it...rev the stink out of it...crash it regualy...it simply won't die...and its a doddle to kick start...one kick every time......easy to wheelie...it has enough power to pull third gear wheelies...I keep up with good riders on kx250's crf250's etc and even the 400's if its twistie...I've got a brand new one coming in a week...the old girl is still fine...I just want a new one...!!!!

only thing wrong with them is the foot pegs fill up with shit easy...!!!

[cheese]

The new 4's also have to have the valve clearence checked every 15 hours. It's not like an old XR250 where they would go and go and go. They are as much, if not more, maintance than a 2 stroke.

From what I've heard about the different brands though...

Honda - have seperate oil tanks for the enigine and gear box, so all your clutch poo's don't get into your engine.

Yamaha - 5 valve head (wicked set up) slightly heavier.

I don't know abou the new Suzuki's and Kawasaki's...

My suggestion though is if you're racing, get a YZF, CRF, blah blah blah, if you're just going to play and it's more as a fun weekend hack, get more like the KLX or Similar. Not as high performance, but you won't be stripping it every 2 days and have your wife having a whine about the garage ss all full of bloody bike parts and can't get the car in there......

[Fryin Finn]

I have had a rather unpleasant experience owning a modern 4 stroke. My WR 450 sucked in sandy water at the Santoft enduro last year through the oil breather pipe - since relocated. This caused enough damage for the engine to be rebuilt. The cost of this work was $4700 and includes new barrel, piston, crankshaft, cams, oil pump, electric starter and bearings.
I loved riding the bike but couldn't bear to rebuild the motor if it ever suffered damage again. I have since traded for a GasGas 250 2 stroke which I rode for the first time at a MX this weekend and absolutely loved it. Nearly as much power as the WR but handled way way better. I may have to replace piston and rings more often but at least it's a job I can do myself.

[Brian d marge]

Maintanance...Honda usa are back logged with parts orders ....gasket sets etc ,,,They ARE a highly strung race engine ...so need the maintance

But ,,I find in the tight stuff the 4 stroke leave enough time per bang to get traction out of the corners ,,,and I cant catch them till 1/2 way down to the next corner ,,,,

One of the best Cr 250 hondas was the 93 to 96 cr range ..so much so that one supercross rider didnt change the bike ,,just the plastic in order to make it look like he had a new bike ..

I find the 4 strokes a little more forgiving when riding ..A bitch to start after dropping them ...and gain more traction

2 stroke lighter ,,,less expensive ... ( I moddded mine for low down grunt ,,,and its MUCH better )

I wouldnt be buying a 4 stroke in a hurry ,,if I can find some 93 to 96 barrels ( Hensteeth) ...I wont change at all ... apart from the newer suspension The 92 Rm ( from memory ) had the valving right ...and the newer CR s have high speed and low speed damping ....So if a set does pop up I will buy it ....

BTW The biggest expense this year has been ,,,Atf oil for the gearbox ( a one race wonder but does make clutch feel lighter ,,,also use it in forks and rear shock,,,,) and chain and sprocket ..Honda genuine ,,which was quite cheap ....oh and a stiffer rear spring

Mx ,,,95 percent the rider ....5 percent the bike ..........

There you go a completely un biased opinion ....

Stephen

[chris]

I'm looking at getting a 450 Motocrosser

Do you want a dedicated MX'er, 'cos a WR450 isn't? If you want something to do MX and trail, GasGas EC range.

[Oscar]

If yer just after a medium sized trail bike, get a DRZ400 (or KLX).
CRF's and WR's are not n00b friendly...

[Coyote]

I'm looking at a 450 Motocrosser type bike as I want to do Supermoto/motard racing (Hopefully enter the S2 class at Taupo and do a few races at Manfeild), but I also want it as a dirt bike cause we can easily access the Masterton MX track so I can get bike time over there, and I want it to be able to register on the road for when I get my full licence. I was thinking of getting the WR as it is road legal plus it has the 5 speed gear box unlike the YZF making it better suited for motard. As far as I know, the main difference between the WR and YZF is the electrics, muffler and cam timing.

I knew 2 strokes would be easier to maintain, but I wanted to know how much worse it is looking after a 4 stroke and whether I could handle and afford it or not. Also wanted to know if it was possible for me to do engine rebuilds given a bit of time or would I have to take it to the mechanic every 4 hours. I was told that a 4 stroke would make a better motard because of their power delivery but I haven't ruled out the idea of a 2 stroke. The main reason why they aren't high on my list is that the only road legal 2 strokes I've seen are the RMX and CRM which aren't any good. Not sure if KTM make a road legal 2 stroke though

As for the pic in my sig, it has nothing to do with this. It's a pic of a road legal Flat Trackker bike CCM have in development, and I just think it looks awesome.

[TonyB]

Modern 4 stroke MX bikes are very highly strung and require a hell of a lot of maintence. For instance the CRF450R. I believe Honda recommends piston replacement every 40 hours. Some racers are wearing them out in 10-20. Even trail riding apparently you would be pushing it to get 60-80 hours. The pistons in these things look like they have come from an F1 car

[Eurodave]

Heres some updated pix of my CB450 street tracker project
Currently Im working on the the paintjob & upholstery. The exhaust pipes in the pix are the patterns that I tacked up & Ive taken them to Autobend to copy & then theyll get black hi temp powder coated.
The mufflers will be replaced with a pair of black shorty reverse cone megaphones.
Next the motors coming out & the frame will get powder coated dark blue
Its great to make some progress after a long time on the back burner!!

[NordieBoy]

As for the pic in my sig, it has nothing to do with this. It's a pic of a road legal Flat Trackker bike CCM have in development, and I just think it looks awesome.

And these...

[Brian d marge]

add to that ...crankshafts..on 2 smokes ....I have just done mine in I was running 40 to 1 as per ,,,but I think I ballsed up the top end jetting not sure will see later...anyway its was pissing down today and the clay went to mud and over the rough the engine was hitting Max Rpm as the wheel spun ....I thought it was bogging a bit ,,,so on one straight I wound it out in second .....and presto ...I have a new crank to rebuild ,,,,

If I do it myself ( as per usual ) its going to come in at 10 000 yen all up

Today was an expensive day !!!!

( and I didnt even get any air time !!)

So there you are another thing to watch out for on a 2 stroke !!!!


Stephen

[Coyote]

Modern 4 stroke MX bikes are very highly strung and require a hell of a lot of maintence. For instance the CRF450R. I believe Honda recommends piston replacement every 40 hours. Some racers are wearing them out in 10-20. Even trail riding apparently you would be pushing it to get 60-80 hours. The pistons in these things look like they have come from an F1 car

Apparently a friend of mine has to do a top end rebuild on his YZF250 every 4 hours Luckily his dad owns Whitehouse motorcycles in Upper Hutt.
I know there's going to be mantainence involved. My brother has a KX125 and almost every weekend is spent working on it.

And if I do get a WR, this is a must: http://www.motoworldracing.com/One-I...phics-Kit.html