Apparently there is a way to shim the power valve on the 2004/05 RM 250's ( FMF does this for team Suzuki offroad) it supposed to give the bike a smoother hit, and loses no boost...
its really easy- the adjuster is on the side of the cylinder. I think you turn it clockwise to make the engine smoother, but i cant remember off hand- look at the manual.
Yes, clockwise is later (smoother). Have an "03 that I've done a lot to smooth-out delivery. You can look for my old thread (03 RM250 woods set-up). One big improvement, and cheap, is a YZ250 reed spacer. (About $15 plus 5mm longer bolts).
How much can you go clockwise. Seems like if you go too tight then the valves won't ever totally open. Also, what does the reed spacer do specifically? Better atomize the fuel?
Micah,
On your bike the std setting is 1/4 turn on the adjuster. 1/8 turn either way is OK but you're right, too tight and it won't open. Too looses and it will move when you land hard off a jump.
I have a 2004 RM 250 and I think the standard setting is 1/2 turn clockwise. I think.
Also, I have heard if you turn it further clockwise, the powervalve opens later and faster, and makes the hit harder. I thought you turned is counterclockwise from standard to make the engine smoother. Am I wrong?
Straight from the Suzuki hop-up information, when you turn the valve cap clockwise the power will be smoother and counterclockwise the power will be more agressive. Maximum range is 180 degrees either way.
Crash, go to www.gregscustom.com click on Suzuki motocycles then click on RM250, on the top right of the page you will see hop up infomation, click on this and your there.good luck.
it depends on the year. The '01 tension is only 90 degrees so 180 either way would be a problem. I think the '00 is a full turn you 180 would probably be OK.
My understanding is that you are starting from zero tension. The adjustment is then clockwise only...just depends on how much.
The governor rod only pushes the power valve system open with X amount of force. So if you have very little tension on the system (Standard is 90 degrees.) then the system will "fly" open quickly. Thus you have an abrupt hit of power. If you put more tension on the spring (another 90 degrees) then the governor rod will have a tougher time opening the system.....which should make it open a little slower......thus you get a less abrupt hit of power.
To much tension and the governor rod won't be able to provide enough force to fully open it (remember, it only pushes with X amount of force). So you have a system that is never at full open and your top end performance would suffer.
If the system has too little tension then the valves can bounce around as RM Guy stated. If you land off a hard jump the jolt could make the valves bounce around.
Sounds like there really isn't much room to adjust the system...and any difference made would be a slight one.