Help with an Old Snowmobile.....

[Cdragon]

I'm sure there are a few out there that know their snowmobiles pretty well...... I'm coming to you for some help.

I bought an old sled for cheap to pull my fishing gear out on the ice. It needed a little TLC, so I have taken the carb off and cleaned it out really well, and I have put some new gas in it and replaced the plugs. It still runs a little shabby. It won't really rev up good. When I do rev it up too quickly, it back fires. I can rev it up slowly and it goes about 25-30 miles an hour. It will idle for about 5 minutes if I just let it run, but then it will shut off.

I need some help with the carb adjustments. There are 2 screws on the carb, but I'm not sure what they do and which one I should be adjusting. Any recommendations?

Here is a pic of the screws..... the one on the right has a spring on it.

Thanks for the help!

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[Theekillerbee]

I'm not super familiar with 2 stroke carbs, but the spring loaded one is your fuel/air mixture screw. Clockwise will make the mixture more rich and counter clockwise will make it more lean. You'll have to check with your sled manufacturer for the appropriate settings. Usually you finger tighten this screw, then back it out about 2 turns, then make minor adjustments from there. Not sure what the one on the left does, sorry.
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[RILEYFISH]

Have you taken the bowl off the bottom and cleaned it all out? There is also a jet that you access from the bottom once you remove the bowl and floats. check these and make sure that they are not clogged with old carmelized gas or sedimint. BE CAREFUL with the floats when removing them. its easy to get them bent and out of whack. Also becareful that you dont let the needle seat valve and spring fall out and loose them
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[Cdragon]

Thanks for the responses. I think I'll take the carb apart again and check it a bit closer. The first time I cleaned it, I was in a little bit of a hurry cuz I wanted to get it going.

Anyone know what the other screw on the left side does?

Thanks again!
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[RILEYFISH]

[cool] Without having it in hand I cant say for sure however could be access to another jet or access to another screw underneath to dissasemble the carb. Soaking it over night in some stoddard solvent will help. even a can of carb cleaner to spray inside and help clean things. Make sure that the jets are not clogged. If old gas sat in there for a year or more, it will raise H#$$ with it. Good Luck
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