xr650r prob's

Hi guys ..i have a xr650r 2002 stock exhaust with end cap removed.The bike runs and pulls really well in the morning but by the afternoon with it sitting in the sun all day it seems to run alot worse.(seems richer).I have the air/fuel mix 2 turns out and the needle clip on the second notch from the top.Any suggestions??Also there is alot of backfire on deceleration would this be due to the end cap removal?Im pretty much a novice at this stuff so would appreciate any advice...cheers

Any other jetting done to the bike at all? THe popping on decel indicates typically a lean condition.

Whats is the carb jetted at, side cover opened up, After market air filter.. :) need more info...

Okay sorry more info..it has holes in side cover and has twin air air filter.I have tried turning the air/fuel mix screw out more but that has no change to the popping.Both the main and the pilot are stock...cheers

There are no problems.

There are only solutions.


Take a look at "Bobs Uncorking" on the following website and make sure you haven't skipped any steps in the uncorking process. Otherwise it'll run like $hit.

The Pig Pen

If the idle jet is still stock then change it to a 68S. Make sure it is a 68S and not a 68. This should cure the problem on deceleration. Some folks have had to add a 70 idle jet to fix this but most have succeeded with a 68S. Make sure you have the power up intake manifold and the power up needle intalled in the carb.

Well there's your problem right there. You have the airbox opened up, and the exhaust opened up, but running the stock main jet. That creates an overly lean condition. The stock main jet is a 125, the jet you should be running is the 175 (for low altitude).

Also make sure the stock needle is set to the 4th position down from top. Unless it has the B3E needle, which should be set in the middle groove. And make sure the intake boot is the opened up unit (40mm unrestricted).

Make sure of all those things and the bike will literally haul ass, BIG TIME!

Good luck with it

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