Jump to content
Sign in to follow this  

upgrade, need jetting?

Recommended Posts

So I did the upgrade on my 06 wr 250 ; air box, exhaust, throttle stop, leak jet, smog pump thing(?) and rode the bike today. There seemed to be no problems through the rpm rage until it hit close to the top, gray wire is still attached. It just sounded strange like it was bouncing off the rev limiter or something. Does this sound like a jetting issue (all jets are stock except leak jet)? I have not pulled the spark plug out yet but just curious as to what yall thought

PS the up grades make this bike rip!!!! I couldn't believe the power difference. Wow, cant wait to take it out with my friends who were puttin it down before the upgrades.

Share this post


Link to post
Share on other sites
it could be the rev limter. did the leak jet make a big diffrence. also did the smog removal thing help get more power?

I did everything all at once so all I can say is they all made a huge difference. I am note sure but I bet the exhaust/ intake did the most good. I am still deciding on the gray wire. I am pretty new to the dirt (160 miles total) and this bike is a screamer for me.

I also turned the air fuel screw to two turns out and put the GYTR needle jet in on the second clip.

How much actual diffence is removing the gray wire, anyone?

Share this post


Link to post
Share on other sites

pull out the grey wire. and see what happens. if you just pull it out you can put it back in if you want.

Share this post


Link to post
Share on other sites
pull out the grey wire. and see what happens. if you just pull it out you can put it back in if you want.

yep. but like me you wont plug it back in. dont cut dissconect it.

Share this post


Link to post
Share on other sites

ok, so the mods are done and I pulled the pug. It looks good, kinda blacker than I expected but definatly not lean. The bike runs great, so do these two things mean I should be ok on jetting?

I did also pull the gray wire so next time i ride I can give some input on that.

Share this post


Link to post
Share on other sites
ok, so the mods are done and I pulled the pug. It looks good, kinda blacker than I expected but definatly not lean. The bike runs great, so do these two things mean I should be ok on jetting?

I did also pull the gray wire so next time i ride I can give some input on that.

I go by Kelstr's jetting method. Find a long straight you can get into 5th and ride it WFO. Keep going leaner on the main until until the bike falls on it's face, then go back to the previous jet. All the time keep a mental note of the bike's sound. When the bike is too rich, it sounds very deep and runs like your it's in 6" of mud with the mud kinda sucking on the tires giving too much drag and not letting the motor pull thru the rpm's easily. When it's too lean it's got a much higher, tinny sound and acts like it's run out of breadth. When your in the ballpark, it sounds crisp and will accel thru the rpm's with ease. Once you've done the MJ, put your attention on the needle clip position. Test this by coming out of corners and rolling the throttle on using the same sound/feel as the WFO MJ test. A deep sound is too rich and usually feels like your in deep sand and doesn't want to rev thru the rpms. Too lean sounds like it's out of breath (if it were human). In the ballpark is not a deep sound and will pull thru the rpm's easily.

It has been my experience that most factory settings are set rich and work OK in the winter but are too rich for hot temps. Optimum jetting changes with temp. Write this stuff down for referral when the weather gets cold again. You'll be changing it then, too.

I have 1 disclaimer to the above: Your bike needs to be geared correctly as too tall of gearing makes it sound too fat all the time and too low of gearing allows it to rev thru the rpm's no matter how far off the jetting.

Share this post


Link to post
Share on other sites
if its black it means jettin is too rich

It's black, but it has very crisp throttle responce. I think I will run it for awhile, I would rather be too rich then too lean. It will take me some time till I can find a place to go wfo in fifth, that is alot faster with the throttle stop changed.

Thanks for the input, do the yama shops have exhaust analizers?

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Reply with:

Sign in to follow this  

×