[cbow8]

I have a 2006 crf450r.
I just bought this bike and it has a problem.

Start it up and it runs perfectly. Get it on the track and after 1 lap it goes nuts. Cutting out backfiring.

I was at track scrambling to fix it before my race...

I swapped carb,cdi,and the fuel tank off my other 06.

History. Bike sat for year or so i thought carb maybe plugged. Swap didnt help.

Im almost positive its electrical like a trigger coil,or stater maybe. Plug wire looked good. Im going to work on this tomorrow. If you have a suggestion throw it up please. Ill try it out.

[cbow8]

Anybody........???? Crickets.....crickets........

Ill post my findings tonight.

[riddler9]

Does sound electrical. If it is a loose wire it will likely run fine on the stand but cutout/pop on the bumps. If it is only after the bike warms up then something is getting too hot.

[Leardriver]

I have seem those symptoms with a plugged gas cap vent. More common on Yamahas due to vent design.
If it starts sputtering and you loosen the cap, hear it gulp air, and the problem goes away, you have found a cheap fix.

[cbow8]

I have not had time to fix it yet.

Its not a loose wire. I can go around the track a couple laps then it just starts running poorly. Like a switch was flipped.cools down its perfect for another couple laps.

Also i did change the entire gas tank carb at track from my other 2006. Im rulling fuel issues out.

I think coil,or trigger coil. If its not that ill be suprised. Not alot of parts on a 06 that could cause it.

[cbow8]

Thank you for the responses. Plugged cap is a great idea. Unfortunately its not that simple this time

[JimDirt]

Have you done test on the items like Coil and plug wire and boot , they have specific tests for them in the Service Manual to rule them out , if they dont fall within the limits they could be your issue , as it does seem electrical since as the bike warms up the issue arises then when the bike cools down its gone , so something is heating up , i would guess coil is breaking down if you have already eliminated CDI , usually when the stator goes out it just stops putting out ,not always , but usually , if you have completely ruled out Fuel system issues , then you are down to just a few things it could be , also only replace 1 item at a time when testing ,

I would look at the coil and plug wire/boot as they have been known to go bad , also make sure its not just a loose plug on the coil , sometimes when the tank is removed the power plug can get caught on the petcock and pull off enough that it will contact and run but when bouncing around on the track it looses connection momentarily , this was a known issue on the 450X ,and happened to me once

[Back2-2]

I have had very simular symptoms when stators starts going bad. Give you trouble for several rides then completely goes out. Your description would lead me to doing voltage and ohms checks on the stator. That may give you some idea what is going on.

[cbow8]

Looks like were on the same page. I cant think anything other than what you guys just stated. Now i just need time to change them out! Work work work.

[JimDirt]

Let us know what you find !!