05 CRF450R - Glowing Red Exhaust Pipe !! ??

TECH HELP. PLEASE!

i have a CRF450R and recently purchased the FMF powerbomb header, i slapped that bad boy on and then did the valve shimming that is required to bring the spacing back to spec. got it all buttoned up and fired the puppy up, sounds mean, but the header started to glow red withing 2 minutes of idling (!!) now, i went back and checked to make sure the timing chain didnt skip a tooth, which i didnt, then took the header off and spark plug out, they both were white, which i read as lean air/fuel mixture. so i took the carb out and opened the pilot screw to 2 full turned out (stock = 1.75) and set the needle to the 5th from the top to fatten up the mixture, i left the main jet alone (168) put the whole mess back together and STILL RED HOT PIPE!!

any ideas??? please email/pm me/post here! [img]/ubbthreads/images/graemlins/confused.gif[/img]

[dave420p]

i had the exact same problem wit mine i just went up one bigger on the main jet it works fine now it takes a few hours to get red hot now i dont know if its supposed to do that at all but i just keep my leg awauy from it

did you changle the needle position or pilot screw adjustment at all?

also since its been glowing after a few hours of riding, and has it caused any damage to the motor? seems like it warp the aluminum...

oh, have you checked what the inside of the header looks like...maybe send a pic if you have one?

frustrating! [img]/ubbthreads/images/graemlins/mad.gif[/img] [img]/ubbthreads/images/graemlins/wall.gif[/img]

[dave420p]

ya i adjusted the needle and screw but i was just srewin around with it so dont really know what i did to it but i know i richend it up a bit because more fuel burns cooler than an engine thats runnin lean and i havent noticed if anything is warping but it runs fine just took it in for service and they said everythings good mabey you should ask your shop they will kno more than me [img]/ubbthreads/images/graemlins/RockOn.gif[/img]