Quantcast
Jump to content

  • Do you own an ATV? Join our Forum!

    As a member, you can post in our forums, upload your photos and videos, use and contribute to our downloads, create your own member page, add your ATV events, and even start your own ATV club to host your own club forum and gallery.  Registration is fast and you can even login with social network accounts to sync your profiles and content.

lindo1951

1992 Yamaha Big Bear Troubles...Please Help

Recommended Posts

Hi everyone. I have a 1992 Big Bear 4x4 that is giving me grief. About a week ago I had the bike running but the idle was very slow. So I adjusted the idle screw and then the bike shut off. I fooled with the screw for a couple of days but it still would not start.

So today I changed the spark plug and took the carburetor off the bike. I cleaned it all up and put it back on the bike. The bike fired up after a couple hits of the starter button and I was very happy. I let it run for a few minutes and it sounded great. I then jumped on the bike and moved it about 20 feet and stopped. The bike still idled away but was a little slow again. I turned up the idle screw a little and the idle speed increased to a good pace. I then went to move the bike again and it started to make sort of a cracking or pinging sound and shut off. Now it will not start again. I should add that it had made those sounds a few times before the bike died the first time on me. WHAT DO I DO!!!!! It is driving me crazy. I hope that someone out there can help me out.

Thanks to all in advance.

Steve

Share this post


Link to post
Share on other sites


I would start by checking things like vavle clearance, compression, make sure you have a good plug and a clean air filter. If it has been sitting for a while, you might drain the fuel and put new gas in it. Also, when you cleaned the carb, did you take it completely apart and clean every hole, and make sure the jets were clear? I would run through all of these things, your problems could be related to any of them. Good luck.

Share this post


Link to post
Share on other sites

Thanks for you're response. It has clean gas, a new plug, and the air filter is fine. I will check the other things that you suggested. Thanks again.

Share this post


Link to post
Share on other sites

timing chain would have to be pretty whipped to do that, but it's possible. I agree I think you should start at the valve adjustments- it is often neglected. check your book for how to adjust the timing chain. most Yammers have the adjuster sticking out of the back, under the carb. you'll need a book to adjust it correctly.

if the chain is loose enuf to rub against something and make noise, then your valve timing is all over the place and that could easily be your slow idle- retarded timing. It's usually a simple procedure but check out a book first.

Share this post


Link to post
Share on other sites

the cracking/pinging sound worries me, and the idle up. it could be valves hitting the piston- not good!

weird idle adjustment could be slack in that timing chain and that could let the valves smack the piston crown. I'll think on it some more.

Swing by Harbor freight and buy an automotive stethoscope- cheap and many uses- including scaring your friends! If not, use a long screwdriver. start it up and put the screwdriver in various places on the engine, put your ear aginst it and see if you can isolate where the sound is coming from. that could tell us a lot.

Edited by Raptor8

Share this post


Link to post
Share on other sites


Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.


  • Similar Topics

    • By Aleksandr Boreesenko
      doesn't idle at times but sometimes when it does as soon as I touch the throttle it just shuts off, what could possibly be the problem? I thank you very much for any help, Thanks.
    • By John Victor
      My father-in-law gave my boy a 1999 350 Big Bear. It's been sitting in a barn for a bunch of years. It runs great! My boy has been riding a couple weeks now and it has developed a squeal coming from the front end when you get off the gas at speed. No noise during acceleration. At first I thought brakes. I took it for a ride and I don't think it is the brakes. I feel it is the front prop shaft U-joints, front differential or one/both axles. I pulled the fill plug on the differential and I can't find anywhere how much gear oil should be in there. My gut says up to the fill opening. It doesn't have a manual. It's wet in there, just don't see any gear oil.

      #1 Should I fill the differential with gear oil up to the fill opening?

      #2 How do I check or know if the u-joints are bad? That looks like a "Big Bear" of a job if they don't need to be replaced.

      #3 What else could it be? I don't think it is the front bearings. I jacked the front wheels off ground and no play in the right wheel. Very little play in the left wheel, looks like the lower control bushing is where that play is coming from. The rubber CV boots look original but all still intact. Wheels spin easily without any noise.

      Thanks for any help!
    • By Dee Morris
      I bought my big bear in 2009, never had a bit of problem with it until last year. It quit starting but still would click when I tried to start it. I replaced the solenoid, the cdi module ( it was burned on one corner) and this year replaced the battery. I have all lights but still will not start and I do not have the clicking when I try to start it. Can anyone give me any ideas what to try next? I haven't had any luck finding videos about the 2008 Big Bear. I'm trying to avoid the expense of sending it to the shop. 
    • By NoDeer
      I have an older (1987) Yamaha Big Bear 350.  I have arthritis in my thumbs.  Is it possible to replace the accelerator with a motorcycle accelerator (ie. twisting the handgrip)?  This would be more comfortable for me due to the arthritis.
  • Recently Browsing   0 members

    No registered users viewing this page.


×
×
  • Create New...