crazycarl7

Member
Oct 14, 2007
46
0
I just bought a 05 yz 250f.the bike is almost brand new but it has sat for the past 8 months. Bike runs perfect but the header pipe glows red when it is running. Is this normal, is the carb dirty, is it running lean? It also pops when decelerating, does that have anything to do with the pipe glowing? please help! Thanks
 

BigRedAF

Member
Jan 9, 2005
739
0
Yes the carb is dirty, probably the pilot and leak jet circuits. Decel pop is a sign of a lean condition. That will get fixed when you clean the pilot circuit and adjust the fuel screw.

Was the choke on when the pipe was red? If so it was rich and excess gas was burning in the pipe. Once you get it cleaned up and adjusted it wont glow red unless you let it idle for excessive time. If it does glow red don't worry it won't melt.

My RMZ glowed red until I finished setting up the idle speed and fuel screw setting. Once dialed in I could only see a very slight red glow in total darkness.
 

crazycarl7

Member
Oct 14, 2007
46
0
glowing header

thanks bro... I just bought this bike and its almost BRAND new! It had sat for a while so i figured something was wrong. Now I have to figure out how to clean the carb!!!??? any suggestions? Is it hard to do?
 

whenfoxforks-ruled

Old MX Racer
~SPONSOR~
Oct 19, 2006
8,129
2
Merrillville,Indiana
You really need a manual. If you have previous experience you may be able to use a parts micro fiche. They do claim the fcr carb is the most sophisticated carb made, well, most expensive. The ap or pilot is the likely culprit to the glowing pipe syndrome. I do believe a dirty filter will mimic a rich condition also. Still, an O2 sensor would be the cats meow to jet with. 4t's to my limited knowledge do not have cheap plugs to jet with, or is readily available to remove and check. Seat time, throttle response and the dreaded popping are easier and cheaper. That wide band O2 sensor will set you back 250 dollars, and a crucial set up job! I have not seen any respectable reviews on the adjustable leak jet, also a bit pricey. That is a jet for the ap circuit.
 


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