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1988 Yamaha Big Bear 350 hard to start

toolman0114

By toolman0114
in Yamaha ATV Forum

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toolman0114 Explorer

toolman0114

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I just put a carb rebuild kit in my Big Bear 350 and it seemed to start fine. Today I take it hunting and its hard to start. Lots of spark, turns over fine. It fires and stalls, then while trying to start it again it floods.

I pull the plug and its soaked.

Only way I can start it (cold) is to spray the plug with quick start and reinstall it. When it fires I bring up the Rpms until it warms up, then it's fine. Sometime I have to pull/spray the plug 2-3 times before it will stay running.

I need help quickly or it will be a long week.

BTW the screw is out 2 1/4 turns

toolman0114 Explorer

toolman0114

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Same problem starting it this morning. What I did notice was when it fired and died on the first attempt the plug wasn't wet. It almost appear like it isn't getting any fuel at the beginning and taking a bit of fiddling to get it to draw. Once it starts to draw gas it runs great.

Getch Apprentice

Getch

Posted
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Maybe fuel petcock needs a good cleaning.

Have you tested that? Pull fuel line off carb and place in a plastic water bottle then turn petcock on to make sure you have a nice flow of fuel.

If its not steady flow...might need cleaning or replacing.

toolman0114 Explorer

toolman0114

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Maybe fuel petcock needs a good cleaning.

Have you tested that? Pull fuel line off carb and place in a plastic water bottle then turn petcock on to make sure you have a nice flow of fuel.

If its not steady flow...might need cleaning or replacing.

Thanx.

Tried that and it's good. Definitely has something to do with the rebuild kit I used.

It was a Shindy kit, package said 89-92 Big Bear but the guy where I ordered it told me would work for my 88. I'm thinking different jet size. Guess I'll have to pay $85/hr for a shop to fix it.

I've never had luck rebuilding carbs.

toolman0114 Explorer

toolman0114

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Ok, it was warmer out thus morning, about 36 F, started right up.

Never had this issue before I rebuilt the carb. My problem was mid-range. I cured my problem, but caused a major one.

Is there nobody out here that can help me?

Seems to be something in the pilot circuit. Could it be the pilot valve (the long pin that slides up/down by the cable) is in the wrong notch. Should I try moving the clip up one notch to drop the pin & lean it out?

Should I change the pilot jet back to the old one?

Should I spend $600 and by a new carb? Or pay $85/hr to have it all redone.

Getch Apprentice

Getch

Posted
Posted

bOY, i WOULD NOT SPEND $600 FOR A NEW CARB...Ebay has several I believe for far less than that.

I am no expert by any means but if it were me, I think I would pull the carb and go through the rebuild steps just to make sure I did not mess up somewhere and that everything is where it should be and clean.

PIA I know but it will give you peace of mind that you did it correctly or you'll find an issue.

I am kind of on the fence when it comes to a replacement or not of the jets and hard parts in a carb when rebuilding. Floats, seals, needle valve sure.

You could put that original jet back in a see what you get.

toolman0114 Explorer

toolman0114

Posted
  • Author
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bOY, i WOULD NOT SPEND $600 FOR A NEW CARB...Ebay has several I believe for far less than that.

I am no expert by any means but if it were me, I think I would pull the carb and go through the rebuild steps just to make sure I did not mess up somewhere and that everything is where it should be and clean.

PIA I know but it will give you peace of mind that you did it correctly or you'll find an issue.

I am kind of on the fence when it comes to a replacement or not of the jets and hard parts in a carb when rebuilding. Floats, seals, needle valve sure.

You could put that original jet back in a see what you get.

I was thinking if pulling and putting the original jets back in it and go from there. I'm wishing now that I didn't touch it, but it ran like crap in mid-range. Should just tried cleaning it.

Oh well, live & learn, crash & burn

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