Has anyone else had any problems with their 400 EX getting hot and getting what appears to be an electrical miss? After several hours of hard riding my NEW 2000 400EX started missing and got to the point where it would not run. I could not restart it. Checked plug, it was perfect, fuses, it was not vapor locking or out of gas. After it sat for about 10 minutes and I was getting ready to get pulled out by a Warrior (AAAHH!!) It started and ran fine for another 3+ hours of hard riding. It started to do it again, on the way to the truck going wide open in 5th gear on a gravel road. Anyone else had similar problems. Taking it to the dealer on Thursday.

 

HAVE NOT HAD THAT PROBLEM WITH MINE,SOUNDS LIKE ITS TOO LEAN CAUSING IT TO RUN HOT?

 

I'm not sure if it really got HOT as in OVERHEATED, the valves never clattered and the oil looked fine and feels fine now, still has viscosity. I'm thinking maybe the ELECTRICAL system got hot and start 'blippin' out. ????
Electrical problems suck!

 

Easy enough to check, when it does it, check for fire at the plug..... Keep in mind that the 400EX is jetted lean from the factory, govt emissions crap...

Look at the color of your header pipes.

 

i had the same problem once, could not figure out
why, when mine was stock the color of my pipes were blue and my buddys were normal, but anways
when i got home i drained all the gas out and put new gas in it and it ran fine then. (when i started out that morning i borowed gas from a buddy it must of been bad)

 

I did check for spark, and it was NOT there when the bike was hot. Pipes are blue-ish in color though. So everyone thinks overheating is due to lean carb and that in turn caused electrical system to overheat and stop producing spark? It was 65 degrees out and I was riding thru a lot of water. I'd bet changing it too run richer would not cool it enough to make that much of a difference. Thanks for the feedback, much appreciated.

 

The mechanic at the Honda dealer I go to told me to only run 87 octane gas in it too, despite the manual saying 92 or higher. He said all the alcohol in the gas just amplifies the already "too lean" settings, which makes for hard starts, and easy overheating. He said re-jetting is overkill (with stock exhaust), but adjusting the gas/air screw should help out.