2003 cr85

[kx400f]

hey i have a 03 cr 85 big wheel, wondering if u guys can help me out, i just put a fresh top end on it and it bogs, i dont know if it bogged before the top end went i got it blown, bogs in low rpm, carb is clean, right gas mixture, and reeds are good. when it his powerband it takes off. it will sometimes foul a plug and will not run again unless i put a new one in..any ideas? thanks.

 

[Matt90GT]

clean the carb better. There is a passage in the bowl that has to be cleaned out, otherwise it will bog.

After that, you need to adjust the carb air screw, needle and jets for your alt/temp. There are jetting stickies all over the forums.

 

[plynn41]

Also, I see that your id is "KX400F"--if you're used to riding larger bikes, a CR85 might make you think it's bogging just because it is so weak in the low rpms. I don't think it has a powervalve (like my son's YZ85), so it takes a second or two for the engine to get serious when you smack the throttle.

 

[Patman]

The little CR's are not known for any low end power. You can clean up the jetting a little but until the rev build not much is going to happen. If you want more low punch send it to Eric Gorr and have him build a super mini engine. You will have more everywhere then pop a flywheel weight on it to make it less stall prone in tight trails if that is what you ride.

 

[kx400f]

yeah tried adjusting the carb cleaned it real good and it still does it. even on the road getting into 5th and start to die down...think i should rejet it? it has an fmf exhaust and i believe thats it.

 

[Matt90GT]

if you are fouling plugs you need to rejet

 

[Patman]

In order to rejet properly you need to know how to read the plug, what the sifferent circuits down and how to properly do the test to begin with. If you don't understand this I strongly suggest picking up Eric Gorr's book.

 

[kx400f]

do i need to buy new jets or is it more of tuning it? Thanks for the help everyone

 

[Patman]

Buy the book you NEED it!