Quantcast
Jump to content

  • Join Today, It's Simple and FREE!

    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.

PKR

1989 Yamaha 350 Big Bear Carb problems

Recommended Posts

I rebuilt the carb on a 1989 350 Big Bear. This is a Gen 1 carb ( 2 cables running to throttle).

Quad starts and runs but I have fuel leaking from the air intake.

Is the float set to high / low?

Does the needle for the main jet need adjusting? I have it on the center groove ( 2 groves above and 2 groves below).

All jets are new, float and needle and seat are new.

 

Thanks for your help

PKR

Share this post


Link to post
Share on other sites


It’s possible that the float is set to low but that would also result in the overflow also leaking.  The small hose that’s attached to the bottom on the carburetor would have gas coming out. 

If you made any adjustments to the needle my guess would be you need to lower it.  

When you put the slide back in the carburetor did it go in properly? And is it sitting all the way down when the throttle is not pressed ? 

Latlsy did you reassemble the carb properly? I’ve made mistakes. The main jet I didn’t tighten it when I rebuilt one of my carbs.  Shit happens.   Double back and re check everything.   

Share this post


Link to post
Share on other sites

Thanks for the tips, I will go through it again and double check everything.

  • Like 1

Share this post


Link to post
Share on other sites

Check the needle and seat as well. might have a bit of crud in it

Share this post


Link to post
Share on other sites

Thanks, I'll check that also

Share this post


Link to post
Share on other sites


Took carb apart and reset the float, it was set to high, had to change out the main jet as it wasn't the right one when I compared it to the old one.

Quad starts nice and idles great. Throttles up nice but when reaching higher rpm's it starts to spray a gas mist out of the air intake and does some small backfires through the air intake. When you throttle back down there is a couple of drops of gas comes out the overflow at the bottom of the carb.

Tried adjusting the air / gas screw but didn't seem to make a difference at high rpm's.

Does the needle on the main jet slide need to be lowered some more?

Looking for where to look next.

 

Thanks

PKR

Share this post


Link to post
Share on other sites

Did you adjust the float enough? In my last post I said set it was set to low, I meant high.  Is it possable that it still needs a slight adjustment ? It might need a hair more.  Also be careful with the back fires and that fuel in the air box.  A back fire can easily lead to the leftover  gas in the air box to ignite and catch fire.  Have you messed around with main jet needle at all? If anything maybe you can lower the needle one notch but if it was in that position prior to working on it then I would leave  it.

lastly have you pulled the spark plug to see what the color looks like ? It’s a good indicator on how the bike is running. 

 

Share this post


Link to post
Share on other sites

Thanks, I will adjust the float a little more. I think I will lower the main jet needle one notch as this carb had been played with before they brought it to me.

 

Share this post


Link to post
Share on other sites

It’s going to take a little time but it will get dialed in. Just keep at it.  It’s a pain in the ass! 

Share this post


Link to post
Share on other sites

This one certainly has been a pain in the ass.

Share this post


Link to post
Share on other sites


Perfectly normal. Just be patient you will get it right and learn a lot while doing it to help the next guy. 

Share this post


Link to post
Share on other sites

Good info, I would drop the float a little more

 

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 Shane Pillar
      Talk about what kind of atv you have and what you do with it.
    • By JacobSlabach
      got 7 atvs off CL recently for a good price.  one of which is a yamaha warrior.  anyone know where the vin is printed on this bike?  Haha good place to start as I do not know year or size yet.  The former owner says needs exhaust ans and clutch work.  he said it ran fine until the clutch cable broke and then I couldn't get the new cable adjusted right and it would grind gears.  things I see:  clutch cable locked up again, no brakes, carb leaking (green with algae around the bowl and has gelled gas stalagtights on it), aftermarket exhaust melted the airbox so I need something different and a new air box.  I would like the use the current exhaust if I can but I have a feeling its a redneck fix as it looks like there is an ace bandage holding it to the exhaust pipe (its an aftermarket slip-on exhaust), so I'm not sure about that- lets get the bike running first.  also, battery (looks brand new, what a shame) is dead, 0 volts.  Otherwise, bike looks to have not been wrecked, and plastics are ok (it sat outside under a 'tarp' for 3+ years since it was run last).  any tips and advise on where to start first would be awesome as this is my first clutched bike (manual).
      the clutch is my main concern- I've never rode a clutched bike so I dont even know what its supposed to feel like.  lol I'm spoiled on my automatic polaris 
    • By Mudrecon
      as the topic says I'm interested in brands of mufflers ur using. I want a quiet (drive up on moose quiet) but performance type. Whos got what? Mines seen better days
       
       
    • By Alex91
      I have a 92 suzuki king quad that seems to be getting way to much fuel in my spark plug hole as I took out plug cranked it over and covered myself in fuel I cleaned carb and fuel filter and fuel pump all seems fine any other ideas
    • By Venom
      Hi All,
      Hoping someone will be able to help.
      I have a 2006 Kawasaki Prairie 700 with twin Keihin Carbs CKVR D32. The Rear Carb is leaking out the side during cranking. it is not the float bowl overflow. It is on the opposite side of the carb from the diaphragm. 
      I got this bike not running and someone had already messed with it. I took the carbs apart , cleaned and rebuilt. Everything went pretty easy.  It looks like it could be missing a small tube between the carbs but I have all of them listed in the service manual installed. See the pic for where it is leaking from...
      Any help would be much appreciated.. Thanks.
       


  • Recently Browsing   0 members

    No registered users viewing this page.


×
×
  • Create New...