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ManDownUnder
21st April 2004, 13:09
OK - me waving my "I don't know shit" flag here.. :blank:

I have an RF900, I got it all tuned up and it's going nice now... but it is stock standard. What are the basic/common tricks to getting more horses at the backwheel.

It also raises the question - what are the best ways of measuring that difference (other than a dyno or tracktime)...

Hmmmm???
MDU

Jackrat
21st April 2004, 13:20
Carb's,pipes,Power commander,Cam if your keen.
Seat of your pants.
:devil2:

James Deuce
21st April 2004, 13:22
It's really hard to improve on what manufacturers do these days, and an improvement at the top end can often mean a bike that is a little harder to commute.

Having said that the Internal Combustion engine is a big air pump. Get it to flow more air and it can burn more gas so you have more power.

The standard breathing mods, are a different muffler, and air filter combined with some careful jetting setup work for your carbs (I'm assuming the RF is carbed).

Unfortunatey (or maybe not) Dyno runs are the best way to do a before and after comparison. Seat of the pants tends to tell us that its going better whether it is or not, because we just spent some cash!

Have fun.

jrandom
21st April 2004, 13:39
Unfortunatey (or maybe not) Dyno runs are the best way to do a before and after comparison.

Indeed. If you give it to a shop to tune, and they're not doing dyno runs after each setup change, then unless they're following a proven recipe for that bike they're as likely to bugger it up as to make it better. Actually solving the air/fuel combustion and flow dynamics of a carburetor and chamber is a hugely complicated problem. Even race mechs just swap jets around and see how it looks on the dyno.

In fact the tuning process for injected engines is similar, it's pretty seat-of-the-pants, tweak the injection mapping tables with a ROM emulator plugged into a laptop until the power curve on the dyno looks the way you want it, then flash it to a chip, plug it in and hope nothing is stressed past its design criteria. The major advantage of injected fuel systems during tuning is the ease of changing the flow parameters, just push a button.

Still, with most factory bikes, you can have them make more power at the expense of emission standards compliance and fuel economy. Like Jim says, a new 'zorst system and air filter, followed by appropriate jetting (if carbed) or remapping (if FI) will probably be your best bet.

Marmoot
21st April 2004, 13:41
What are the basic/common tricks to getting more horses at the backwheel.

Wheelie the bastard :yes: :yes: :yes:
That effectively doubles the horsepower put onto the back wheel

750Y
21st April 2004, 13:48
depends a lot on where you want the performance gains. cheapest seat of the pants gain is throw a larger rear sprocket(1 or 2 more teeth) & it'll take off faster in the gears but ultimate top speed will come down by a few mph & it'll throw out your speedo. don't waste your money on pipes,filters etc unless you have a specific goal in mind. once you throw on a pipe then filter you will need to retune etc which can chew up the cash also if you're doing jets blabla & clocking up dyno time. imho, spend it on suspension & your bike will eat up the road better & you'll be able to travel quicker with more confidence.

jrandom
21st April 2004, 14:10
don't waste your money on pipes,filters etc unless you have a specific goal in mind.

More ponies! He did mention that specifically you know. Going to different sprockets doesn't give you more power, it just changes the torque multiplication constant. Yer right though, I think it's good to be clear about the time and cost implications of performance tuning. In the end if you want more power you have to burn more fuel in the same amount of time, either by being more efficient with what already flows through, shoving a greater amount of fuel and air in with each combustion cycle or running more cycles, ie revving higher.



imho, spend it on suspension & your bike will eat up the road better & you'll be able to travel quicker with more confidence.

wot 'e said. New Ohlins rear shock and a fork swap to a GSXR1000 front end (if that's possible on the RF) and you'll be going faster than you ever thought possible on that wheezy old thing...

Hitcher
21st April 2004, 15:24
Wheelie the bastard :yes: :yes: :yes:
That effectively doubles the horsepower put onto the back wheel

Hmmmm, I see that somebody wasn't listening during 6th form physics...

Hitcher
21st April 2004, 15:26
depends a lot on where you want the performance gains. cheapest seat of the pants gain is throw a larger rear sprocket(1 or 2 more teeth) & it'll take off faster in the gears but ultimate top speed will come down by a few mph & it'll throw out your speedo.

Surely this depends as to whether your speedo sending unit works off the final drive or the front wheel?

750Y
21st April 2004, 15:42
Surely this depends as to whether your speedo sending unit works off the final drive or the front wheel?

yep sure does


New Ohlins rear shock and a fork swap to a GSXR1000 front end (if that's possible on the RF) and you'll be going faster than you ever thought possible on that wheezy old thing...

LMAO

DEATH_INC.
21st April 2004, 15:53
A decent full exhaust is a good start.Most will net a good gain on an older bike and usually shave a fair bit of weight off too,which also benefits handling.
Also just a good freshen up/tune can do wonders if she's a bit tired.
Next is aircleaner/carb kit,then cams.all bolt-on.Look into big-bore kits,this will give good hp/torque gains but requires engine dissasembly,while you're in there may as well get a good port job done too.
If you want real gains then a turbo is the go,but you're getting quite serious if you go this far.

The 2nd option would be the pipe,and a re-valve/rebuild on the suspension.Or a complete front/rear swap.PB did a test on a blade a while back spending the same on suspension and hp and got much faster laptimes outta the bike with the suspension work.And fit the best tyres you can afford.

The other option is loose everything that you can off the bike/yourself.Power to weight is where acceleration comes from and losing weight is as good/better than gaining hp as it will benefit handling too.

Take her down the quarter is the way to measure real gains in acceleration,and of course a track to measure yer handling gains.

ManDownUnder
21st April 2004, 16:13
Cheers guys...

Yup more ponies is specifically what I want - I can then gear up or down from there...

Something I note has been avoided is playing with the fuel. Additives or changing the octane rating works? I realise there will be knock on effects with timing etc which also raises the question...

How much difference will 91 Octane vs 96 (or 98) really make?

MDU

James Deuce
21st April 2004, 16:18
Cheers guys...

Yup more ponies is specifically what I want - I can then gear up or down from there...

Something I note has been avoided is playing with the fuel. Additives or changing the octane rating works? I realise there will be knock on effects with timing etc which also raises the question...

How much difference will 91 Octane vs 96 (or 98) really make?

MDU

My TRX runs better on 91. Depends on what the manufacturer specifies.

Higher octane fuels actually have a faster flame front and can in effect make the engine run cooler due to being more efficient. Too cold is as bad as too hot, but the stuff you get from the pumps isn't going to make that much difference.

Additives are bollocks. Some of them are just vegetable oil.

ManDownUnder
21st April 2004, 16:19
My TRX runs better on 91. Depends on what the manufacturer specifies.

Higher octane fuels actually have a faster flame front and can in effect make the engine run cooler due to being more efficient. Too cold is as bad as too hot, but the stuff you get from the pumps isn't going to make that much difference.

Additives are bollocks. Some of them are just vegetable oil.

...noted...

jrandom
21st April 2004, 16:23
How much difference will 91 Octane vs 96 (or 98) really make?

hoo boy, opening a can of worms there! I think we've thrashed the technical side of octane ratings pretty well in past threads.

Higher octanes are more resistant to pre-detonation, ie, they will burn smoothly in a higher-pressure environment. Hence they tend to be necessary for harder tuned engines. If your bike hasn't damaged itself running on 91 so far then you're not going to see anything better happening on a higher octane fuel.

But try BP/Mobil 98 anyway, can't hurt. You might notice the power coming on smoother. I know I do on the FXR.

Really though, if you want them ponies, you need to do like Death says and get that new exhaust and a retune as a starting point. Call the nice men at Colemans for quotes and advice.

F5 Dave
21st April 2004, 16:29
There’s a 970cc kit for the RF or you could look at an 1100 top end but that loses the water cooling. Apparently the run better a little hotter than they currently do & I am trialling a hotter thermostat to see.

They seem to like advancing the ignition somewhat. This can be done with a stepped ignition advancer key or rotor, but I have just rotated the pulsar plate anticlockwise & been careful to keep the clearance down to about 10thou. You need to slot the plate to do this (under RHS sidecover). I have only just done this & it seems to aid pickup, but think some detonation is heard under 2k rpm. Will try 96 to see if this goes away. Seems to aid midrange & perhaps topend.

K&N airfilter will require a bit of jetting so wouldn’t bother unless fitting a aftermarket jetkit. My bike is keeping the std pipe as it’s my touring bike. If you lower the gearing be aware that they vibrate a bit at higher speeds so this may bring it down to usual cruising speed.

The ports are huge & if I get the time (the YZF project is likely to receive more attn) I will experiment filling them in a bit. This should help topend as well as through the range. Making them bigger rarely helps, despite the folklore.

PS the bars are at a dumb angle if you get wrist ache try some adapter bars from F1. Cost $230 inc courier which seems like a lot but they are well made & worth it.

Jackrat
21st April 2004, 16:50
Now we're talking,big bore,big valves,Cam it up,Blue print it,Hot ignition,Lose wheight,chuck away all the heavy stuff.
Ah stuff it buy a harley, spend heaps an still go slow. :Oops: :calm: :calm:

Oscar
21st April 2004, 17:27
OK - me waving my "I don't know shit" flag here.. :blank:

I have an RF900, I got it all tuned up and it's going nice now... but it is stock standard. What are the basic/common tricks to getting more horses at the backwheel.

It also raises the question - what are the best ways of measuring that difference (other than a dyno or tracktime)...

Hmmmm???
MDU

Ahem, at the risk of being rude...why don't you just learn to ride it faster? I've met plenty of guys with more horsepower than brains...

F5 Dave
21st April 2004, 17:33
The logical conclusion of that argument is to buy a 10 speed & pedal like 10 bastards.

More midrange power always feels better on the road, easier & lazier to ride & although the RF has a sweet engine it’s top end overshadows it’s midrange.

wkid_one
21st April 2004, 17:34
I agree - in most instances you are the only limiting factor on the bike. The bike will do a hell of a lot more than your mind will lead you to believe it can.

I would only be worrying about increase performance when you are riding the pants of the bike you are on....and in that case, you would also have to weigh up whether you aren't just better off upgrading....

jrandom
21st April 2004, 17:35
Ahem, at the risk of being rude...why don't you just learn to ride it faster?

Ahh, he probably doesn't necessary want to break lap records or even point-to-point road records, he just wants it to make a pretty noise and try to pull his hands off the bars. Fair enough too, we only live once. If you want your toy to make as much horsepower as possible, more power to you, says I...

Of course one could argue that MDU would do better to just trade his RF in on a gixer if that's what he's after, but I understand the attachment one develops to a machine... it's funny, some guys swap bikes every year or so, never satisifed, and other guys stay with a demonstrably 'inferior' machine for ages, tweaking it, tuning it, fiddling with it, but those guys often seem happier than the ones with the latest rocket in their garage and the biggest hole in their mortgage...

750Y
21st April 2004, 17:36
Cheers guys...
Yup more ponies is specifically what I want - I can then gear up or down from there...
MDU

DeatchINC is right about making horsepower.
also Craig? at colemans, has an RF so he'd be a good guy to ask also.

Oscar
21st April 2004, 17:44
The logical conclusion of that argument is to by a 10 speed & pedal like 10 bastards.

More midrange power always feels better on the road, easier & lazier to ride & although the RF has a sweet engine it’s top end overshadows it’s midrange.


Ahhh, we're just being a bit silly now, aren't we?
He's talking about an RF900, I assume - so he ain't short of the odd pony.
He'd probably benefit more from a suspension tune up and a decent set of tyres, before looking for more berries.

Racey Rider
21st April 2004, 17:49
Higher octane fuels actually have a faster flame front and can in effect make the engine run cooler due to being more efficient.

Are you sure you got that the right way around? I thought we had said 91 had a faster flame front than 96. Can anyone confirm?

jrandom
21st April 2004, 17:55
Are you sure you got that the right way around? I thought we had said 91 had a faster flame front than 96. Can anyone confirm?


Hmmm. Faster flame front? Not sure that octane would directly affect that. It DOES affect the likelihood of an uneven burn under different pressures. If it did have something to do with overall burn speed, I'd expect a lower octane to burn faster, not slower.

Hell, I need to get me some chemistry books.

James Deuce
21st April 2004, 18:31
Are you sure you got that the right way around? I thought we had said 91 had a faster flame front than 96. Can anyone confirm?


That was the answer my petrologist brother -in - law gave me.

FROSTY
22nd April 2004, 00:22
might be teaching gramma to suck eggs here but I understand that rf900's vary in engine specifications depending on where it was soposed to go.
We got a lot of rf900's that were for other countries -some with much lower horsepower due to sound/smog emmission laws
The cheapest/easiest option to raise horsepower might be to find out what carb setup,cam angles,etc the south african spec bikes have and set your bike up the same

BurnCycle
22nd April 2004, 02:22
I’m surprise no one has mentioned the one fundamental ‘rule’ when it comes to more power… How much power you want all depends on how much money you’re willing to spend!

There are simple and effective ways to make a bike fast that don’t deal with the engine. But yes, they have some adverse effects (some more minor than other), it all depends on what your willing to put up with.

1. Weight reduction. Have a good look at the bike and see what can be removed or replaced with lighter materials. Simply removing the tool kit can be around 2kg. Passenger pegs and tie down points are other things that can go (depending on bike). Plastics can be replaced with race fairings (though maybe not on the RF). Wheels are another way to utilize the existing power of the engine. Less rotating mass the engine has to move the better the power is put to the ground. A simple aftermarket rim can weigh in at half that of the stock wheel. Here’s also where a 520 chain/sprocket conversion can be a benefit with less rotating mass. Also consider the tires you use. That 190/50 weighs quite a bit, try a 180/55.

2. Driveline. As mentioned before changing the gear ratio can have a big difference in the way the bike feels. A few (2 to 3) extra teeth on the rear sprocket will make quite a noticeable difference. Yes your top speed will be down, but how often are you pushing that hard? As mentioned before, converting to a 520 weight chain/sprocket may also be beneficial.


3. Rider. Can the rider loose a few kg? For every 4-5kg lost the bike can utilize an extra HP not trying to move a lard arse around. Training also goes a long way and a simple book is a good place to start.

As for the engine (simple stuff)…

1. Exhaust. This also goes into weight reduction. The stock pipe is nothing short of a boat anchor. Ditch it.

2. Jet kit. Larger mains and pilots as well as a few shims will get the right amount of fuel you need. Most jet kit’s come with recommendations for applications. This is a bit of a shot in the dark but a good starting point. Without dyno tuning you won’t know if you’ve got it right.

3. Air filter. Also mentioned previously was the air pump… More air in combines with more fuel and a better way to get it out all equate to more power.

And the not so simple stuff…

This is where big $$$ comes into play and you may want to start considering a new bike as finding upgrades for the RF become a bit of a heart ache.

Lou Girardin
22nd April 2004, 06:58
Fit an aftermarket can, Neptune are good value. K&N or similar filter, static timing advance plate, Dynojet kit and time with a good dyno operator.
It'll cost a bit but you'll should get 5 to 10 more hp and fatter midrange.
Then again, the RF's not exactly slow as stock.
Lou

Eddieb
22nd April 2004, 08:38
Or another option that hasn't been mentioned but would be relatively cost effective for the gains.

Sell the 900 motor and put in a GSXR1100 motor. Huge instant power gains, up to an extra 25bhp depending on the donor model and thats before tuning.
Lots of extras available, hugely tunable with lots of info on the net and people who have tuned them before.
You must be able to get an 1100 motor for around a $1000, if that nowdays, minus whatever you can sell/trade the 900 motor for.

They are all based on the same motor so a bit of research should reveal a model that will slot into the 900 frame with little or no modification.

That would be my bet for a good gain and relatively little expenditure and still have plenty of scope to go much further. I would think it would be a lot cheaper than can, filter, dyno time etc and produce up to 5 times the power gain even before tuning..

F5 Dave
22nd April 2004, 08:57
Well I mentioned the 1100 barrels, but a bit optimistic on the 1100 motor price. GSXR motors are sort after & $3k would be a bargain.

ManDownUnder
22nd April 2004, 09:01
Ahem, at the risk of being rude...why don't you just learn to ride it faster? I've met plenty of guys with more horsepower than brains...

That ain't rude - it's a bloody good question.

The answer is a simple one - I've just spent a bit of money on the bike and got it going quite nicewly - which made me wonder... what else is out there, make it go better?

Timing tweaks, air in/out tweaks, fuel tweak, compression tweaks etc.

I used to work on jet engines so I could tune one of those for you (ok, I'd need to hit the books again but the principles are there) but never spent much time around these piston based things with a spanner in hand.

For me the answer to "why" is simply why not - what can I learn and what fun could I have tweaking and playing with it.

As for me being the limiting factor on my bike... HELL YES! I took it out to a pukekohe raceday and proceeded to be the backmarker all day (and loved it I might add). I don't pretend to be anything more than a road rider with a few years under my belt... cautious as hell (apparently falling off at great speed hurts - no?)

MDU

James Deuce
22nd April 2004, 09:12
That ain't rude - it's a bloody good question.

The answer is a simple one - I've just spent a bit of money on the bike and got it going quite nicewly - which made me wonder... what else is out there, make it go better?

Timing tweaks, air in/out tweaks, fuel tweak, compression tweaks etc.

I used to work on jet engines so I could tune one of those for you (ok, I'd need to hit the books again but the principles are there) but never spent much time around these piston based things with a spanner in hand.

For me the answer to "why" is simply why not - what can I learn and what fun could I have tweaking and playing with it.

As for me being the limiting factor on my bike... HELL YES! I took it out to a pukekohe raceday and proceeded to be the backmarker all day (and loved it I might add). I don't pretend to be anything more than a road rider with a few years under my belt... cautious as hell (apparently falling off at great speed hurts - no?)

MDU

I've always been hurt worse in low speed accidents. The times I've fallen off over 160km/hr on the track I've barely scuffed my leathers.

On reflection I reckon suspension upgrades would give you more reward for the amount of money spent. You'll be able to brake harder and later, and get on the gas sooner. You'll probably get better value out of your tyres as well, as you'll use more rubber across the surfaceof the tyre :)

Oscar
22nd April 2004, 16:09
That ain't rude - it's a bloody good question.

The answer is a simple one - I've just spent a bit of money on the bike and got it going quite nicewly - which made me wonder... what else is out there, make it go better?

Timing tweaks, air in/out tweaks, fuel tweak, compression tweaks etc.

I used to work on jet engines so I could tune one of those for you (ok, I'd need to hit the books again but the principles are there) but never spent much time around these piston based things with a spanner in hand.

For me the answer to "why" is simply why not - what can I learn and what fun could I have tweaking and playing with it.

As for me being the limiting factor on my bike... HELL YES! I took it out to a pukekohe raceday and proceeded to be the backmarker all day (and loved it I might add). I don't pretend to be anything more than a road rider with a few years under my belt... cautious as hell (apparently falling off at great speed hurts - no?)

MDU

That's a very honest appraisal, and I gotta say that there is something to having a few trick bits on yer bike, especially ones that help it sound good (I have a SXC muffler on my KTM), but I can show you scars where I learnt that too much power can be a bad thing.

I spent years riding off-road with mates who were a bunch of enduro hotshots (Motu will attest to what a bunch of lunatics they are). In this rarified atmosphere I used to figure that my own riding skills were pretty duff - I spent a lot of time following the pack. What actually happened was as I got better, they got better, so I still ended up as the rabbit of the bunch, but of a bunch with very high standards.

Recently I started riding on the road and adventure riding, and I am now constantly appalled at the lack of basic riding skills shown by a large percentage of the people I see. Young and old guys with all the fruit on expensive motorcycles (on & off road) who are an accident looking to happen.

My advice to you (and to any other road riders), is if you wanna hone yer skills - go off-road. This is not a new or radical thought, the Kenny Roberts School in Spain uses XR70's to teach pupils the finer points of braking and traction.

Get yourself a cheap trail bike and find a piece of land, a trial ride or whatever. The lessons happen at lower speeds and mistakes are neither as expensive or as painful as road racing..,.

Motu
22nd April 2004, 17:01
The other extreme happens too - you can be a better rider than your peers,spend your whole time showing off,but have never been pushed - when you get to ride with better riders you find out you are a no body - you could even over reach yourself.Trials was and still is a big shake up for me - no matter how good you think you are - you start at the very bottom,those who can't be humble quickly disapear.

I'll back up Oscar on the dirt skills as the best foundation blocks,it will only improve your riding.But I'm sure that KTM could really fly if it didn't have to haul so much un necessary weight. :finger:

MacD
22nd April 2004, 17:01
might be teaching gramma to suck eggs here but I understand that rf900's vary in engine specifications depending on where it was soposed to go.

Does anybody know how to tell which country model a particular RF900 is? I have the RF900 PDF manual with the country codes, but I've yet to work out how to tell from the bike (without pulling it apart and checking cam markings etc). Supposedly there's meant to be a code marking on the carbs (as jet sizes and settings differ) but I couldn't find one...I think I have an Australian model?

:confused2

ManDownUnder
23rd April 2004, 11:43
Does anybody know how to tell which country model a particular RF900 is? I have the RF900 PDF manual with the country codes, but I've yet to work out how to tell from the bike (without pulling it apart and checking cam markings etc). Supposedly there's meant to be a code marking on the carbs (as jet sizes and settings differ) but I couldn't find one...I think I have an Australian model?

:confused2

I can't directly answer your question but looking through the manual I see there is a difference in a couple of areas. One of them is the lock nut on the back wheel, some regions require a split pin and castlatted (sp?) nut, other regions were fine with doing the bastard up tight (mine is the no split pin variety).

Likewise in the light swtichblock, some regions have a headlight light on/off switch, some don't (mine doesn't - just the dip switch...).

Looking in the manual I see there is a list of codes indicating which country/model it is...

E-02 = England
E-03 = USA (except California)
E-04 = France
E-15 = Finland
E-16 = Norway
E-17 = Sweden
E-18 = Switzerland
E-21 = Belgium
E-22 = Germany
E-24 = Australia
E-25 = Netherlands
E-28 = Canada
E-33 = California (US of A)
E-34 = Italy
E-39 = Austria
E-53 = Spain

I couldn't find it on the bike (parked downstairs in the dark... which really didn't help..) but I assume it's going to be on one of the frame tags up around the steering head?

A big giveaway for me is the fact there is a Noise label on the LHS of the steering head - upon re-inspection of the bike and manual... if you have this longish label (rectangluar, white on mine) mentioning noise levels, then you have either the E-21 or E-24 bike (Belgium or Oz).

I'm picking mine is Oz...
MDU

Oscar
23rd April 2004, 11:47
The other extreme happens too - you can be a better rider than your peers,spend your whole time showing off,but have never been pushed - when you get to ride with better riders you find out you are a no body - you could even over reach yourself.Trials was and still is a big shake up for me - no matter how good you think you are - you start at the very bottom,those who can't be humble quickly disapear.

I'll back up Oscar on the dirt skills as the best foundation blocks,it will only improve your riding.But I'm sure that KTM could really fly if it didn't have to haul so much un necessary weight. :finger:

You can be so hurtful sometimes...http://www.advrider.com/forums/images/smilies/bncry.gif

I'll pick out a special hill fer you on LWII...

DEATH_INC.
23rd April 2004, 12:00
Pretty sure a higher octane fuel actually burns slower,that's why they can take more timing/compression without pre-ignition.
Use the lowest octane fuel you can without pre-ignition for most hp :yes: .
The GSXR1100 engine won't work,the rf has downdraft carbs,the gixx's stick out the rear :disapint: .
One other option is nos.....good fun and fairly easy to fit if you just want the odd blast.... :banana:

F5 Dave
23rd April 2004, 12:09
Thanks MDU, I think I’ve seen that label, I’ll go check mine tonight. I noticed something written in some wog language (read; anything us ignorant mono-linguistic folk don’t understand) so I’m guessing mine is French, but to confuse things I was told the engine was replaced when a boat ran into it in the garage or some other crazy thing.

Hey I wonder if they change the headlights for LHS from Euro?

Seems to go pretty damn well top end (it would give my 750 a go) & the carbs are not tamper proofed.

Who cares if they are as ugly as sin? Most bike for least money award I reckon :scooter:

James Deuce
23rd April 2004, 13:34
Pretty sure a higher octane fuel actually burns slower,that's why they can take more timing/compression without pre-ignition.
Use the lowest octane fuel you can without pre-ignition for most hp :yes: .
The GSXR1100 engine won't work,the rf has downdraft carbs,the gixx's stick out the rear :disapint: .
One other option is nos.....good fun and fairly easy to fit if you just want the odd blast.... :banana:

You are correct, however I should have said that it burns more evenly at higher compression ratios. The only reason you need high octane fuel is to control the burn process at higher compression ratios to avoid preignition. However it does burn faster in high compression engines because the act of compression helps ignition.

Sorry.

merv
23rd April 2004, 14:04
But I'm sure that KTM could really fly if it didn't have to haul so much un necessary weight. :finger:

I've got a funny feeling now I've bought a lighter dirt bike that the gross weight combo of me and machine won't be much different than when I bought my DR250 five years ago. Luckily I haven't kept record of the statistics - but my quack probably has.

Oscar
23rd April 2004, 14:14
I've got a funny feeling now I've bought a lighter dirt bike that the gross weight combo of me and machine won't be much different than when I bought my DR250 five years ago. Luckily I haven't kept record of the statistics - but my quack probably has.


Don't worry about Motu - he's a grumpy shortarse...

MacD
23rd April 2004, 15:22
I can't directly answer your question but looking through the manual I see there is a difference in a couple of areas.
Likewise in the light swtichblock, some regions have a headlight light on/off switch, some don't (mine doesn't - just the dip switch...).

[snip]

I'm picking mine is Oz...
MDU

Yeah, I followed the same process of elimination and came up with the E-24 Oz model too.

For some reason Suzuki doesn't seem to stamp the country code on the ID/VIN plate along with all the other info. The dealer claimed it was the "full horsepower model" and it seems to have plenty enough for me anyhow ;)

Also I'm not sure they're that ugly anyhow, I know they had that rep, but I quite like the look of them!

pete376403
23rd April 2004, 16:12
Pretty sure a higher octane fuel actually burns slower,that's why they can take more timing/compression without pre-ignition.

Thats correct. When Honda were running the extremely high (for the day) revving 5s and 6s back in the 60's, they had to run regular grade petrol as the high octane stuff burned too slowly - by the time the fire got going it was on the way down the pipe.
Methanol is even slower burning (and burns cooler than petrol, too, ie less energy released) but can take very high comp - my old cast iron JAP speedway motor ran about 16.5:1, yet never really got hot. IIRC the old iron XR harleys ran about 8:1 yet melted on race petrol (hence the later alloy XR)

MacD
23rd April 2004, 16:47
so I’m guessing mine is French, but to confuse things I was told the engine was replaced when a boat ran into it in the garage or some other crazy thing.


If it has French and English it's probably the Canadian model...

Mmmm...5pm.... :apint:

F5 Dave
23rd April 2004, 16:49
Yeah beer time I think

Lou Girardin
24th April 2004, 04:01
Does anybody know how to tell which country model a particular RF900 is? I have the RF900 PDF manual with the country codes, but I've yet to work out how to tell from the bike (without pulling it apart and checking cam markings etc). Supposedly there's meant to be a code marking on the carbs (as jet sizes and settings differ) but I couldn't find one...I think I have an Australian model?

:confused2

There were a lot of EO3's brought in. Check your carbs, have they got tamper proof plugs in the pilot screw holes?
Lou

F5 Dave
26th April 2004, 09:23
Ok smarty pants/es, I have a non castellated axle nut, a noise label, but also have French written on the labels, seeing as Neither the Stellas or the Aussies speak wildly good French this makes it likely it is French. Or Canadian. Or Tahiti? :sweatdrop It has a light switch. And it has a Label with E6. Not on that list, oh dear.

Further I went for a ride with a friend who also has a RF but with castellated axle nut & no light switch. We did a series of roll ons, but trying to stay a bit legal we did them from 70 – 100 ish & this sort of meant only 3-4thou starting point. I was riding his & it walked away from mine every time.

Hardly scientific & perhaps our wind on time was off a bit & he does weigh 10 or so kg more than me :Pokey: but pointing to a difference in spec or setup. Maybe my advancing of ignition doesn’t work at low revs. Would be interesting to get it on the dyno.

May want to check the header pipes for differences which is one of Suzuki’s restriction tricks. The carbs appear fine (& adjustable).