# Carborator Problem?



## Fishfoote (Jan 2, 2001)

I bought a 72 Lynx recently and it blows flames out the carborator spuratically at full or close to full throttle. Does anyone know what might be causing this????


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## Burksee (Jan 15, 2003)

Several possiblilties here;

1) Fouled plugs. if this is a twin cylinder are both plugs burning the same?

2) Lean air/fuel mixture - carb restricted, needs carb o-haul or replacement. 

3) Timing, even w/CDI timing of the pickup is important.

4) Lean air/fuel mixture caused by internal air/vacume leak - caused by bad crankshaft seals and/or gaskets in/on the engine.

5) If you have an external fuel pump, check the hose from the crankcase to the pump could be leaking air into the engine. The fuel lines themselves could be letting in air to the carb.

Bottom line, sounds like you got a lean air/fuel mix issue.

Hope this helps!


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## Fishfoote (Jan 2, 2001)

I'll check it out within my minimum abilities...thanks


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## Burksee (Jan 15, 2003)

I'm trying to remember, and I'd like to try and help if possble.

Your 72 Lynx, is it a twin or a single cylinder?

The engine usually has some kind of tag on it. If so what does it say?

Is it a free-air, fan cooled? or (but I doubt on a Lynx) is it liquid cooled?

Does it have a diaphram or slider carb(s)?

One or two carbs?

Does it have an external fuel pump?

What kind (NGK, Champion) and what numbers (B8ES, N-4) are on the spark plugs?


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## fishfinder#74 (Jan 17, 2003)

Just get a carb rebuild kit,one or more of the diaphrams is ripped or disinagrated.Give it a try it will work.Goodluck!


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## Fishfoote (Jan 2, 2001)

Thanks for looking - I'll print out what you've asked and find as many answers as I can. I do know that it is a one cyclinder, single carb. air cooled and the champion plug was just replaced with NGKs...I think I don't have the numbers, but will get them. Thanks again.


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## Fishfoote (Jan 2, 2001)

think there'd be a carb kit for a 30 year old machine? where would a person get such a kit?


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## fishfinder#74 (Jan 17, 2003)

Oh most certinly, call stevens cycle sales or try spicers there is many aftermarket parts for these older machines. also try bills market on m-61 in sterling he probaly has a carb on the shelf for ya.he has quite a few older artic cats out back.


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## Burksee (Jan 15, 2003)

Im not so sure thats got a diaphram carb on it? It could have a single mikuni on it?

If it does have a diaphram carb and you want to put an o-haul kit in it you can find'em at any repair shop that does snowmobile/small engine repair. I get most of my stuff at Recreational Leisure in Farmington, MI.


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## Fishfoote (Jan 2, 2001)

How will I know if it has a diaphram on it?


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## Burksee (Jan 15, 2003)

A diaphram carb has mulitiple plates on the bottom. The fuel line goes in either the side or the bottom. 

The throttle cable on a diaphram carb attaches to the side and a "butterfly" plate opens when you move the throttle.

See if you can find the manufacures name on it?

Diaphram carbs are usually Tillitson's

Does it have a choke "flap" (plate) on the back of it?

Slide carbs are usually Mikuni's

Most sliders the throttle cable go down thru the middle and attaches to a "slide" that go's up when you open the throttle.


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## Fishfoote (Jan 2, 2001)

I may have to post a photo - sliders and butterflys sounds like a mixed drink to me...


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## Fishfoote (Jan 2, 2001)

Could this possibly be a wiring problem? The reason I ask is that before all this started, I tipped the machine on its side (dragging a deer ) and it would start after that. It didn't have any spark to the plug. I took it to a guy to get it fixed and he said he had to fix a wire - I never asked which wire, but it seems that if the only thing that was messed with before the problem with the carb was wiring, maybe that's the cause???


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## Burksee (Jan 15, 2003)

Unlikely, backfiring thru the carb is 9 times out of 10 a fuel issue. 

If you tipped it over you probably got dirt shook loose some where in the fuel systemand into the carb? Not trying to sound offensive but it sounds like you over your head and you need to enlist the services of a knowledgeable service guy?


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## Fishfoote (Jan 2, 2001)

No offense taken. I'm going to run it up north, a friend of mine has a mechanic up there that's supposed to be a wizzard with older sleds. I did change the plug last night at the recommendation of the guy that fixed the wire - seemed to help a bit, but something's still going on. Couldn't get the starter to work, I think the battery's toast - wouldn't even work getting jumped off the truck and even when I got it started the lights wouldn't come on...man I love older sleds


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## Burksee (Jan 15, 2003)

Cool, Let me know what he finds. Your right "Some" of the old sleds are great fun to tinker with and ride. (*Note to self: Dont ever by another 83-89 V-Max!) Just dont plan any long "expeditions" with them! 

Good Luck!


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## Fishfoote (Jan 2, 2001)

I talked to the guy that last worked on the sled and he thought it was just a bad plug. I changed the plug and the backfiring has decreased about 90%. It still does backfire after idling if I go right to full throttle, but it is an older sled and I don't do that as a general rule. I'll probably use it as as secondary sled (I also have a 77 Cheetah that runs perfect...knock on wood) for ice fishing then have someone go over it. Thanks for all the suggestions/help -


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