Jump to content

Overheated exhaust right after starting

Recommended Posts

Hello everyone, brand new to the forum but been around and worked on bikes for quite a while. I recently acquired an old dirt bike and have been having some problems.


The bike is a 2003 WR450f. The bike was previously in good running condition, but due to an injury with the previous owner, sat for about a year in a garage. When I got the bike I drained the tank and put fresh gas in. The bike was really really difficult to start. My leg got tired and sore from kicking it so much, even after talking with the previous owner and ensuring I was doing the correct starting procedure for the bike. Eventually I was able to use one of my other bikes to jump this one and hit the starter long enough to get it to start. 

Within a minute or two the exhaust pipe was bright red. I read through one of the threads on this forum and it recommended cleaning out the pilot jet. I pulled the carb and gave it a good cleaning. Pilot jet did look pretty clogged, but otherwise the carb looked ok. Out everything back together and tried to start it again. After giving the carb bowl time to fill, I tried kicking it again. I was again unable to start it without jumping one of the other bikes and using the electric start. The exhaust pipe again turned bright red within a minute or two.


I did read through the FAQs and saw the part stating the bike will get hot and the pipe might turn red if idling for a while, but this seemed a bit extreme. Is this normal? Should I break down the carb again? Something else?


Thanks for the help.

Edited by Redleader571

Share this post

Link to post
Share on other sites

Replace the pilot jet with a BRAND NEW ONE

Clear the passage above it with small copper wire

REPLACE your battery. You have a dead cell

Get an R&D fuel screw and learn how to use it


You made no mention of your state of tune.

If it is near stock, it will achieve overheating in a minute due to the restrictive pipe.

If it has been uncorked, you will get another minute or two before overheating.

Share this post

Link to post
Share on other sites

Create an account or sign in to comment

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

Reply with: