red hot exhaust on 426

I let my 2001 yz 426f warm up on choke for about a min then idle of choke for about 5 min while getting boots on when i came back to my bike the exhaust was glowing pinkish red and coolent was dripping out of hose that ran down the side of my bike is there something wrong??

yah, you overheated the damn thing letting it idle.... they are meant to fly, not sit for extended periods of time!

so then its fine to ride

yeah you can't leave a liquid cooled 4 stroke to sit idle. air needs to be flowing through the radiators to keep it cool. when i ride my 400 through the tight stuff when it's getting dark i can look down and see the pipe glowing. it goes away when the trail and the throttle opens up though. the coolant dripping was the coolant boiling over and going out the overflow due to excessive heat build up from little to no air going through the radiators.

ok cool just got this bike a couple months ago im glad its not broken

It'll be fine, just make sure to check your coolant level and refill if you need to.

had the same problem with my rmz,it could be that the radiator cap is shot and is not sealing pressure in your system anymore.try a new rad. cap and try ice coolant instead

ok i will try that thanks

ok i will try that thanks

Your rad cap is probably 100% fine :lol: This is normal under the circumstances!

yeah 5 minutes is an insane amount of time to let a bike warm up!!!!

a glowing header is completely normal for a 4 stroke in dim lighting, that is probably the most common question asked here on tt by new members. It also is normal for the bike to get a bit hot and drip out some coolant if it sits for too long. Check your coolant level when it has cooled off to make sure you haven't lost too much and you should be good to go.

I had the same bike and it would do the same exact thing. Now you can imagine how easily you can dent that header especially if you lay it over on a rock or tree root while riding a tight technical trail. Your cap is probably fine. If anything, check your jetting and make sure your not running too lean and do a coolant flush. Lots of coolant to choose from. Coolaid works great for me. Good luck.

If you need to let your bike idle for an extended period of time, (and 5 minutes is what I'd call exstended) for maintenance, tuning and such, place a house fan in front of the rads to direct air into them. It needs moving air through the rads to keep the bike cool.

good looking out bro, i m now running engine ice as coolant.plus i changed the radiator cap.already flushed fluid too.seems to be working, just at idle 4-5 minutes seems to heat up.must be normal. thanks bro

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!


Register a new account

Sign in

Already have an account? Sign in here.


Sign In Now