YFZ 450 exhaust glowing red

Hey, i just bought a 2004 yfz 450 and it has a complete yosh d exhaust. Im not sure what type of jetting but the air box lid is off and a aftermarket air filter, not sure what brand. aso it has a temp guage for the antifreeze, what should this run at? And my exhaust glows red after running for about 5 minuets, is this normal.  I dont want to ride it and damage anything. any thig to help me get on the trail asap would be awesome.    Darren from New Jersey  

you could have too much fuel going into the cylinder.
if so it could go into the exhaust and ignite there from the heat of the exhaust.

most likely between 150 and 180 degree's, i don't have my books here, but it should be somewhere in that range.  

wolf1 is there anything i can do to try to fix this problem?  adjust ments on carb maybe? again dont know what main jet is in the carb now?  

and the temp is at 200 now during idle then the fan kicks in and only goes down like 10 degrees  

yeah as long as it is going down when the fan kicks on.
200 isn't a far stretch for a 450cc 4cycle engine.
just check that fuel mixture screw because the exhaust shouldn't be glowing red.  

Hi,

I have a 2006 yfz 450. It's all stock and my exhaust glowed red the first time I fired it up.

It's totally normal.
Just keep in mind its a high preformance motor.  

hey wolf1,

okay i have an 04 yfz 450, it is completley stock.  It runs great on bottom end and mid-range, but once you hit the higher rpms in 5th gear it just doesn't pull like it's supposed to...it just dies off. I have noticed that on most yfz's that my friends have that the head pipe glows red, but mine doesn't. it has a 158 main jet. i tried pulling the airbox lid off and taking the baffle out, but it didn't seem to make a difference. i don't know what jet i should mess with or if i should tune the fuel/air mixture screw. i bought this bike used and just rebuilt the engine with all factory parts, and i retarded the exhaust cam one tooth to make it like the yzf timing if that makes any difference. any suggestions?  

advancing the timing normally gives you more power,
retarding is ok, but advancing the timing by 4 degree's will give you more torque and acceleration.

if you removed the baffle and airbox lid then you need to readjust the fuel/air mixture screw to allow for the extra exhaust and air intake flow.
turning the fuel/air mixture screw to the left will add more fuel to the mix, while turning it to the right will add more air.

just mark where the fuel/air mixture screw is setting and make your adjustments in 1/4 turn increments. let it run for a few minutes between 1/4 turn. and keep up with how many 1/4 turns you make to it so you can get it back to factory and try the other direction if neccessary.  

just got an 06 yfz and pipe glows, it's normal.  
YAMAHA-Lean Mean Blue Machine

hey i have a yfz 450 too.. mine glows red so thats perfectly normal, they just get HOT! I just run regular coolant in mine..  

darren512:
Hey, i just bought a 2004 yfz 450 and it has a complete yosh d exhaust. Im not sure what type of jetting but the air box lid is off and a aftermarket air filter, not sure what brand. aso it has a temp guage for the antifreeze, what should this run at? And my exhaust glows red after running for about 5 minuets, is this normal.  I dont want to ride it and damage anything. any thig to help me get on the trail asap would be awesome.    Darren from New Jersey

hey i have a yfz 450 too.. mine glows red so thats perfectly normal, they just get HOT! I just run regular coolant in mine..  

ALL YFZ 450 HEAD PIPE'S GLOW RED.THATS WHY I CALL THEM GLOW STICKS WHEN IM OUT ON THE DUNE'S.THERES TWO DEFFINITE WAYS TO MAKE YOUR YFZ RUN COOLER.CHANGE YOUR COOLANT TO ENGINE ICE COOLANT,, AND RUN SEMI SYNTHETIC LUCAS 10-W40 ATV OIL.BY RUNNING LUCAS OIL IT WILL DROP YOUR TEMP BY 10 DEGREES AND THE ENGINE ICE COOLANT WILL DROP IT EVEN MORE.I ONLY ADJUST MY FUEL AIR MIXTURE SREW WHEN MY YFZ WAS POPPING AND RUNNING NOT LIKE IT SHOULD BE.I ALSO CHANGED MY AIR FUEL SCREW TO A AFTER MARKET ONE TO MAKE IT REAL EASY TO ADJUST....THE COOLER YOUR ENGINE IS THE MORE PERFORMANCE YOU WILL GET AND LESS WEAR ON YOUR ENGINE BUT THEY ARE DESIGHNED TO RUN HOT.ALSO WEAR RIDDING BOOTS AND IT WILL KEEP YOUR LEG FROM BURNING OFF  

which way is left and which way is right though when looking at the wheeler adjusting the fuel screw? my wheeler is popping and banging decelerating and blowing flames and is laying down top end, can't even get to my rev limiter now in 5th, feels like its laying down and taking a nap.  

To wolf, I have a quick question about my 2008 yfz450. I was riding around and well i didn't notice it at first but the stock pipe was red hot. It was a night ride and it was red hot. Now I talked to the dealer I purchased it from and they told me that was normal being that its a high performance motor and all that compression coming out of the exhaust, causes it to burn up. Now that was the first time I ever noticed that. Just wanted to make sure that was normal. Is this true. I know that I have asked this next question but what is a good quiet exhaust to buy. Im not into loud because of the trails I'm on wont allow that. just want a performance pipe that isn't louder than the stock but adds to the performance of the quad. Please help for I'm an idiot when it comes to this stuff!  

Hyosung um mtx 450r anyone know anything about these? good or bad? help before a friend buys one.