Jump to content
Sign in to follow this  

uncorked xr650r throttle issues

Recommended Posts

Hey guys I’m new here with my new to me 2001 xr650r and I’m loving it so far! I’m in San Diego California at about 500ft and 75 degrees with a 68s pilot jet and 175 main with a b53e needle. The bike also has a procircuit slip on can with stock headers and the full airbox mods and round boot from carb to head. However when i crack the throttle open fast it will bog/die if I don’t return the throttle to the idle position. I understand it’s a constant velocity carb and not a pumper but is it normal for them to die with throttle chopping? Can a spark plug or airfilter affect this? I ask because I have yet to clean the airfilter or change the plug since purchasing from the previous owner. This is troubling for me when I’m riding whoops sometimes as the power will cut out and the nose will dive putting me in a scramble!. Below i have attached a video of the issue and a picture of my BRP for your viewing pleasure. Any help with my problem is greatly appreciated and constructive criticism is welcome! thanks! :ride:[/size][/font]

Heres the video link!!!!!

xr650rpic_zpsa0dbe712.jpg

Edited by nikolaus98

Share this post


Link to post
Share on other sites

Had a problem with mine,new air cleaner solved it.Boy did I feel stupid,but figured it out on my own.Most hondas are bullet proof,start out with the small stuff

Share this post


Link to post
Share on other sites

I think ill go with a new UNI airfilter once paydays swings around. Hopefully that will help out!

Share this post


Link to post
Share on other sites

I think ill go with a new UNI airfilter once paydays swings around. Hopefully that will help out!

Share this post


Link to post
Share on other sites

Nope ...that's (almost) as good as gets with the stock carb. You can go one more fine adjustmevt with a richer slide cut-away.

By the way it has a simple slide carb not a CV carb. The CV carb is on those "L" (ladies) bikes...hehe

  • Like 1

Share this post


Link to post
Share on other sites

Nope ...that's (almost) as good as gets with the stock carb. You can go one more fine adjustmevt with a richer slide cut-away.

By the way it has a simple slide carb not a CV carb. The CV carb is on those "L" (ladies) bikes...hehe

YEP its not a pumper carb its gonna have a gap if you flip it open fast.......THROTTLE control or replace with a pumper carb

AGREED those Ladies bikes are same, but when i was rocking the L i never had that problem either, and dont now with my R either..... im just not wild on the throttle...

Share this post


Link to post
Share on other sites

ok thanks guys! I just wanted to check in and make sure this was normal! I think ill save the pumper carb until after I get a new truck to hual the BRP around in.

Share this post


Link to post
Share on other sites

Ya, overall i don't miss my pumper Edelbrock,iv'e gone back to stock,, You do get used to it.

But this last adjustment on the stock carb REALLY helped. I cut 40 thou or so off the bottom of the slide,thus reducing the slide cut-away and making the trasition from idle to 1\4 throttle much like a pumpers' reaction.

Share this post


Link to post
Share on other sites

Ya, overall i don't miss my pumper Edelbrock,iv'e gone back to stock,, You do get used to it.

But this last adjustment on the stock carb REALLY helped. I cut 40 thou or so off the bottom of the slide,thus reducing the slide cut-away and making the trasition from idle to 1\4 throttle much like a pumpers' reaction.

you had .040 machined off the bottom of the slide???? very interesting as i have a 2nd motor im building up now..... give some details and pics maybe too???

Share this post


Link to post
Share on other sites

you had .040 machined off the bottom of the slide???? very interesting as i have a 2nd motor im building up now..... give some details and pics maybe too???

Simple as it sounds,Chuck it in a lathe,,and then taking ..040"(anywhere from.025"-.060") off the bottom will make the slide cut-away smaller or simular to 'less angle' Thus making it a richer slide. Have done this for years in jetting carbs.

Share this post


Link to post
Share on other sites

you machine this 40 thousanths off the bottom of the carb where the "half moon" area is? allowing the slide to sit lower making the A/F mix richer? seems good in theory! my question is how does one chuck it up in a lathe without galling the smooth finish that allows the slide to move smoothly?

Share this post


Link to post
Share on other sites

you machine this 40 thousanths off the bottom of the carb where the "half moon" area is? allowing the slide to sit lower making the A/F mix richer? seems good in theory! my question is how does one chuck it up in a lathe without galling the smooth finish that allows the slide to move smoothly?

A machinist with a good lathe can do it without harming the slide.Also, The outside is hard coated and is very durable. Or one could replace the slide with a smaller # cutaway...if you can find one.

Share this post


Link to post
Share on other sites

Dont make me come over there! :lol:

The CV carb is on those "L" (ladies) bikes...hehe

  • Like 1

Share this post


Link to post
Share on other sites

You can lessen the bog you get when opening the carb quickly by making the mixture richer. Raise the needle one notch, or try going up a step or two on the pilot jet. Opening up the air filter, as well as the exhaust, often require these steps. Also, if you haven't done so, check valve clearance.

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  

×