wr400 stalling/dieing at low speeds/loss of power

3 replies to this topic
  • calathan

Posted July 01, 2012 - 06:05 PM


I have a 98' wr400 and I have recently had issues with my bike stalling at low speeds.

A little history:
A week or two ago I took my bike to the sand dunes. I took a jump and when I landed I lost control of the bike and bailed out. I was fine but the bike had issues starting (the engine was most likely just flooded with gas) and then once we got it going it was running super fast. What I mean is that when in neutral the RMP's were as though the choke was pulled out, and while riding back to the car to call it a day, the bike was running super hot. I figured it was the idling pin that got turned or something in the crash. (is that what it is called?)

The Problem:
I didn't think much of it at the time. A few days later I decided it was about time to change my oil filter so I replaced the oil filter and put in some yamalube oil (first time using yamalube). About a week later I started it up and it seemed to be running back at normal RPM's without me doing any tinkering, so I decided to take it out with my buddies for some trail riding. Out on the trail it was running super different. First, going into first from neutral I had to let go of the clutch farther before I started to take off. I had to use the clutch WAY more often on the trails, and when slowing down for super tight switchbacks I even stalled it twice. I also had issues going up hills. I would make it nearly to the top and then just lose all of my power, even in first/second gears. The thing is I know that isn't normal because I've ridden these trails many times and never had these issues. I stalled it on some hills that even beginners wouldn't have issues with. I also noticed while going down hills shifting down a gear didn't have the same slowing power as normal.

So anyways, I'm not sure if I have given enough information for anyone to help me out but I'm at a loss. I've got no power and it's super frustrating not being able to keep up with my friends 125 2strokes. I used to be the one that just powered up hills like a boss, but now they are.

  • calathan

Posted July 12, 2012 - 09:45 AM


I'm still trying to find answer so if anyone has any hints (even another link to somewhere) that'd be awesome :)

Visit the ThumperTalk Store for the lowest prices on motorcycle / ATV parts and accessories - Guaranteed
  • Pooley

Posted July 12, 2012 - 08:59 PM


The dune thing was most likely the carb leaking air around the couplings. The hard landing knocked something loose. High RPM at idle, and hot = lean. Lean means too much air.

Remove the carb and clean out every jet and then blow it out with compressed air. After you put it back on the bike, make sure all the rubber couplings are properly seated and attached. Inspect the rubber couplings for cracks too. Once everything is back together, start the bike and while idling, spray some fluid like WD40 or starter fluid?? (not sure exactly what to use) around the rubber couplings. If the RPMs change JUST from spraying something, you've got an air leak.

  • calathan

Posted July 16, 2012 - 08:55 PM


I'll have to give that a shot and see what happens. Thanks for the info!


Join Our Community!

Even if you don't want to post, registered members get access to tools that make finding & following the good stuff easier.

If you enjoyed reading about "" here in the ThumperTalk archive, you'll LOVE our community. Come join ThumperTalk today!

The views and opinions expressed on this page are strictly those of the author, and have not been reviewed or approved by ThumperTalk.