XR650L riders...

...just wanted to see if I could get some suggestions. My bro just bought a new XR650L and was saying it seems pretty tall geared. Are any of you changing out sprockets? Also, the place he bought it put on a FMF pipe and re jetted. He says it's popping on de-cel so I thought I would see if anyone has some jetting suggestions too.

Thanks in advance!

-Mark

i dont know about the XR's, but i know on my DR that engine pop on decel is normal due to a very lean condition. it is not abnormal and lets people know you are there. now if it is actualy back fireing,(very loud !!!!) that could be a problem. i am thinking it is normal.

I swapped mine out for a 48t rear sprocket, but it required a longer chain.

Removing the emissions crap with a block off kit will get rid of the popping on decel.

As for jetting, I'm at 55/158 with the FMF Q4 muffler. (4,000 ft.)

I also did the "Dave's Mods" to the carb - http://www.4strokes.com/tech/honda/xr650lcarbmods/

Thanks guys. Backwoods, I noticed that the Dave mod says considered almost mandatory for 93-04 XR-L's. Was that because of the date it was published and it would apply up to '09's? Sounds like a guy could drop a tooth on the front sprocket and get close to what you have for gearing without having to lengthen the chain.

Supposedly the dealer removed all the emission stuff. It has been pretty cool out so I'm thinking it may be a little lean on the pilot for the current temps. May be about right on if we ever get normal weather again.

Yes Sir, the Dave's Mods applies to all years.

Good luck to your Bro, he'll get it dialed in.

On some bikes there is a thing called a PAIR valve which feeds air from the air box to the exhaust port for emissions. If you plug the port in the airbox, it will stop the pop(s). If not, install a larger pilot jet.

PeteN95 wrote:

On some bikes there is a thing called a PAIR valve which feeds air from the air box to the exhaust port for emissions. If you plug the port in the airbox, it will stop the pop(s). If not, install a larger pilot jet.

I was wondering about that. I made the thumpertalk.com WR450 and 250 smog removal kit for them for several years. I knew on that bike if you changed exhaust without blocking the air pump it would pop.

Thanks again!

make sure you don't have an exhaust leak somewhere before the muffler too, this will cause a pop also, i used a dynojet jet kit on mine, took the baffle out of the air box, guttet stock muffler, de-smog, take your head pipes off and clean the weld drool from inside of the pipes. after you do this, the low end torque an throttle response is much better, an you may not wan't to change the gearing. i ride mine with the real dirt bikes, on some very tight trails, an as long as nobody in front of me is slowing me down i get along pretty good with the stock gearing . but if you would feel more comfortable lower geared, just drop a tooth on the front sprocket. what ever you do to it, will only make it better an you can always put it back if you don't like it.

big jer wrote:

make sure you don't have an exhaust leak somewhere before the muffler too, this will cause a pop also, i used a dynojet jet kit on mine, took the baffle out of the air box, guttet stock muffler, de-smog, take your head pipes off and clean the weld drool from inside of the pipes. after you do this, the low end torque an throttle response is much better, an you may not wan't to change the gearing. i ride mine with the real dirt bikes, on some very tight trails, an as long as nobody in front of me is slowing me down i get along pretty good with the stock gearing . but if you would feel more comfortable lower geared, just drop a tooth on the front sprocket. what ever you do to it, will only make it better an you can always put it back if you don't like it.

believe me, big jer kicks ass !

I just posted some info in the Rate your bike thread. I have listed some of the stuff I did.

https://pnwdualsport.forumotion.net/general-bike-discussion-f16/rate-your-bike-t935.htm

If I am going down a hill and using compression my bike loads up a little and will pop. Never been a real issue for me.