Quantcast
Jump to content

96 Yamaha Big Bear Replacing carburetor jets

mailman1

By mailman1
in Yamaha ATV Forum

 Share

Recommended Posts

mailman1 Apprentice

mailman1

Posted
Posted

I have a 96 Yamaha Big Bear 2x4 with a 350 engine and have replaced the original carburetor with a Zoom  Zoom version twice to no avail. I am thinking about rebuilding my original carb. and was wondering if the same mikiuni jets that you would use  for a snowmobile will work in the ATV or are they different? Thanks

davefrombc Mentor

davefrombc

Posted
Posted

If the  jets are the same size  and thread as the originals   they should work.  If the motor  is   not modified, or  the quad is nor  being regularly  driven  in very  high altitude  areas,  why  change the  jets? They  don't wear  out. All  the  carb should need  is a  good cleaning. If there  is damage to the  floats or obvious wear  on the float needle  and seat ,  they   could be replaced as well as gaskets  and any  diaphragm  the  carb  might   use. Don't  change the  jet sizes .  I'm  sure the engineers that   made the selection  for that  motor  knew  what they  were doing  choosing  jet sizes. The  only reason  to    change  size  would be   for a modified  motor that would demand  more  fuel as a result.  I think  more people  have carb problems  when  they  start  fiddling  with  jet  sizes than   those  that  stay  with  stock  on their  machines.

mailman1 Apprentice

mailman1

Posted
  • Author
Posted

Thanks for the reply. One other question that I forgot was do you know if the jets, etc. from the Mikiuni will fit in the Zoom Zoom carb. or do they have their own specks.?

DPDISXR4Ti Explorer

DPDISXR4Ti

Posted
Posted

Is your fueling issue a tendency to stall at idle?  That's the problem I've had for years, and I've considered swapping in one of those carbs that you see all over eBay for $35.  And yes, I have tried cleaning the carb, but to no avail.

mailman1 Apprentice

mailman1

Posted
  • Author
Posted

I'm in the process of cleaning my original carb right now as like I've said before  I have had two Zoom Zoom  carburetor's and nether one would work. They seem to stall out when you try to give it gas, pops, bangs, stutters, etc. and then if you keep feathering it,  it  might finally take off. I'm not a fan of Zoom  Zoom to say the least.  I didn't have any problem with the Co. in replacing the carburetor it's just that they don't work the way they should.

DPDISXR4Ti Explorer

DPDISXR4Ti

Posted
Posted

So it sounds like replacing the carb with a cheap after-market unit isn't a good idea.  It seems to me that if there's a jet which is used at idle which I could step up one notch, that could be a resolution.  But I really don't know enough about how this carb works to know if that's feasible.  Anyone know better?

DPDISXR4Ti Explorer

DPDISXR4Ti

Posted
Posted
23 hours ago, mailman1 said:

There should be a thumb screw on the carb to adjust your idle, might try that and see if it helps.

Yea, I tried messing with that some a few years back and it didn't seem to yield good results. I forget exactly now so it might be worth messing with again.

mailman1 Apprentice

mailman1

Posted
  • Author
Posted

Also there is a brass slotted head screw I believe on the bottom of the carb., try turning it all the way in (keep track of how many turns) and then back it out 2 3/8-2 1/2 turns out for starters.

DPDISXR4Ti Explorer

DPDISXR4Ti

Posted
Posted
On 3/13/2018 at 1:17 PM, mailman1 said:

Also there is a brass slotted head screw I believe on the bottom of the carb., try turning it all the way in (keep track of how many turns) and then back it out 2 3/8-2 1/2 turns out for starters.

I just went out and quickly looked for this but didn't find it.  But it's kinda hard to see the bottom-side with the carb installed, so maybe it's just hiding? 

  • Admin changed the title to 96 Yamaha Big Bear Replacing carburetor jets
mailman1 Apprentice

mailman1

Posted
  • Author
Posted

Well it's been several day and I finally had a chance to get the original carb back on after I cleaned it. It starts right up better than before but now I get what sounds like a misfire on one cylinder and I know there's only one cylinder to start with so does or has anyone ever had this problem and is there a way to take care of the problem? By the way I did take the plug out and clean it and also when I had the other carburetor on it wouldn't miss just buck, cough, and spit when I tried to add power.

Coyote251 Contributor

Coyote251

Posted
Posted
1 hour ago, mailman1 said:

Well it's been several day and I finally had a chance to get the original carb back on after I cleaned it. It starts right up better than before but now I get what sounds like a misfire on one cylinder and I know there's only one cylinder to start with so does or has anyone ever had this problem and is there a way to take care of the problem? By the way I did take the plug out and clean it and also when I had the other carburetor on it wouldn't miss just buck, cough, and spit when I tried to add power.

Have you checked your timing? If you have it running and idling around the correct RPM, that would be the next thing I looked at. When you cleaned the carburetor did you verify that everything was in spec? Did you put a carburetor rebuild kit in, when you cleaned it? Pay very close attention to the float height measurement, especially if you are having any starvation or flooding issues. Also, if you didn't put a carb kit in you might want to. If the gaskets and O-rings or needle seat are not 100%, it can cause a lot of grief. A kit for my Suzuki is worth about 15$, and if I remember the last time I bought one for a Yamaha it was about the same. 

Clean-up or replace your plug, if your bike hasn't been running properly. Also make sure that the gap is close to what is recommended in your manual.

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.

×
 Share
Go to topic listing

  • Similar Forum Topics

    • hengstserepair
      2000 Yamaha Breeze 125 slips in Forwards, runs fine in reverse
      By hengstserepair
      Howdy ya'll. I am working ona 2000 Yamaha Breeze 125. It was in rought shape when I received it and I am working through issues as they pop up. The quad had been sitting for years. I was able to get her running again, but I need your help with the following issue:
      I don't trust the transmission yet and I don't want to make problems any worse. So, I haven't pushed things hard at all. Low rpms, less than 5mph in reverse.

      Nuetral: Runs as expected
      Reverse: She seems to be driving fine at slow speeds. Going into reverse at idle is fine, coming out of reverse back into neutral won't work (the shifter is just stuck). As soon as I turn off the quad, I am able to shift around without any issue.
      Forward: It slips. It seems to only transfer power to the wheels on a smooth surface and going slightly downhill. When shifting into forward at idle, there is a clacking sounds during the transition. Shifting back to nuetral works just fine.

      Other Notable Symptoms: There was old oil in the vbelt and when I was tuning the carb, it starting blowing out of the CVT cooling vent at the front of the quad. Made quite a mess. There is positive crankcase pressure due to piston blowby, that I have not decided whether or not I am going to fix (customer budget dependant).  Since the oil was old, much darker than the new oil that is in the crankcase, I am thinking it seeped past a bad seal while it was sitting for years. The oil that was in it when I first got it had gas in it.

      Thoughts: I am thinking maybe there is an issue with the clutch. I worry about the old oil intermingling with the dry centrifugal clutch. I was thinking my next step would be to take the cover off of the clutch and inspect it.

      Let me know what you all think. Any advice and ideas is greatly appreciated. This is only the 3rd quad I have worked on and I have a lot to learn.

      Lorne
    • Rockbottom
      2008 Yamaha Big Bear 400 will not start
      By Rockbottom
      2008 400 big bear was running now will not start
      have power to relay, in neutral, press start have power to starter but nothing happens starter does not turn
      i have good ground at battery to frame and added ground from wire harness to frame beside batter/ frame ground
      blue white wire to cdi has power with key on
      I believe the neutral lock out is working since is was before i shut it down
      if i put  it in gear and hit the start button with key on the relay does not click or send power the starter
      The 3 wires at the relay have power with key on
      What should i test next?
      thanks ahead
    • Mister907
      2000 Yamaha big bear 400 won’t start
      By Mister907
      Hi guys, I have a 2004 big bear 400. Last winter while plowing the driveway, I heard a loud pop from the left side of the engine. It continued to run as I looked for leaky fluid, but then died shortly after backing it up and won’t start now. The oil light comes on when I try to start it, no noise or anything else. 
      No blown fuses that I can find.
    • jeffinotown
      2007 Yamaha Big Bear IRS Short
      By jeffinotown
      Hey guys and gals. I've been working on my friends 2007 big bear IRS. Unfortunately after 3 different people got their hands on it and only made things worse every time.  After months of finding just crazy problems everywhere. I'm finally at the point we're its almost 100% !!! But I'm getting a short somewhere between the 4xW switch I believe. I managed to by searching the internet like a  fiend, got my hands on an official Yamaha wire harness for the year and make. But I don't have the numbered component list and to be honest. After hours of going through and making everything so it's  easy to reference. If anyone has a picture of the referenced components. I would be forever in your debt. I've spent hours marking up the blown up diagram so it will be easy, for any possible future repairs. Please and thank you. Here's a picture of what i have so far.  Unsealed it in plastic so oil and crap won't spill or get smudged. This damn things worth it's weight in gold.              Thanks Jeff                2007 Yamaha big bear 400 IRS.       YFM40FBW
    • toe420
      Tips for rebuilding starters
      By toe420
      I got a couple yamaha moto 4 225cc quads. The guy gave me several old starters with them. I see kits are available to rebuild them but does anyone have tips or tricks for doing it? I haven't rebuild a starter before so im not sure what to look out for. 

COMMUNITY SECTIONS

ATV FORUMS

QUADCRAZY MEMBERSHIP

Be a part of best online community of ATV riders and join thousands of people who love ATVs! Share your ATV photos, videos, ATV rides, get help with your ATV and more. Not a member?

SIGN UP TODAY

ADVERTISE WITH US

FOLLOW US ON

  • Automotive Webmaster
×
×
  • Create New...