YZ400F Not Kicking/Starting

5 replies to this topic
  • xBRIANx

Posted May 18, 2008 - 03:55 PM


My buddy just bought a USED 99 YZ400F. Well, we take it out this weekend, and it starts up fine, so, we start riding around in our field and he says it keeps bogging when hes on the throttle. Well, after riding it for a few minutes, it stalls. Check to make sure there is gas, petcock is on, everything that we can see is fine, oil.. everything fluids wise. Well, we goto kick start it, and we can pretty much jump on it, and its not moving (The kickstarter, that is.) And as far as the decomp. lever, well, we took it off, becuase the guy we bought it from, said we didnt need to use it. So Im assuming he put auto decomp. cams in it before we got ahold of it. And prior to that, its always started fine. My only thing is, is that it wont even bump start either. So not only is the kickstarter like, stuck, it wont bump start either. Any ideas? Suggestions? things I could check and maybe that would be the problem?.. THANKS!!!!

  • 1998YZ400F

Posted May 18, 2008 - 08:07 PM


sounds like it does need to the decomp lever. i would look at the cams to be sure and go from there.

  • metalm0

Posted May 18, 2008 - 10:09 PM


Possibly related to the kickstart gear? I broke one of them and the piece got lodged in between the gear and the clutch gear...

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Posted May 18, 2008 - 10:23 PM


I think the key here is it was bogging while riding....something was/is not right. Hopefully the engine is not seized. check for cracks in the case around the kickstarter (if you are lucky). if so then the kickstarter is wedged. If not then pull the plug, and try to turn engine over. It prob ran real lean, due to a plugged/dirty carb, and overheated, then seized. Hopefully not, but that is my guess, see what others post.

  • YZ400f_99

Posted May 19, 2008 - 09:07 AM


Well I brought my bike out this weekend put in a good 5 hrs on it. Runs great. It's a 1999 YZ400f.

Came back from a ride, went to go start it a few hrs later and the kick keeps stopping on me half way down, like a lot of resistence. Checked all my fluids everything seems fine. No cracks anywhere that i can see by visual inspection. I can get the bike started and eventually kicks without the stoppage/resistance. I thought that the engine had seized but once I get her started the bike runs great and all the power/torque is still there which wouldnt happen if it was seized am I right?

Sometimes it starts up right away without the stoppage/resistance. And sometimes it takes a good 10-15 trys then kicks no problem.

It didn't do this before I know somethings up. But like I said I can get her going and she runs great. As you can tell I don't know much about these bikes. What do you guys recommend I do or look at next? All fluids are fine, and no cracks anywhere that i can see.

p.s I am starting it right as well with the decomp lever. Once I had it figured out before I took it out this weekend, i could get it going everytime 1-2 starts and never resisted on me or locked up when kicking. I know somethings different but find it weird that it runs fine and still has all the power when I get it going. I'm not riding it anymore till I get this figured out.

What's my next few steps to figure out what the problem is? I have a friend who rebuilds bikes and knows what he's doing that will be down next weekend who im sure will take a look at it.

Any suggestions and comments appreciated. Thank you.

p.s.s I never had any issues with it bogging at all, all weekend even after the kick start went all wonky. It does pop a little on decel though, going to take the carb apart and clean it.

  • YZ400f_99

Posted May 19, 2008 - 12:12 PM


UPDATE: Stumbled accross something on the forums and figured it give it a try (because come to think of it my buddy did stall it about 4-5 times as hes riding in to low of revs barely giving it throttle, and it started then) So I put the bike in gear and rocked it back a few times. Started her up first try, it still does it but it only did it once out of Id say the 10-12 times I tried.

Started her up about 6 times in a row first kick.

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