'75 300

[beam]

Hi all.

I'm new to snowmobiling and my first sled is a '75 300 that I picked up.

When I first got it, it ran pretty well. But now, I'm having issues with it. Basically, it doesn't idle...it is either flooding out or too lean, and when we keep it going, there is no power...(flooding?) It has enough power to move me, but not at a very fast speed. If I get it running down hill so that it "kicks in" a bit, I get repeated backfires (too lean? too rich?)

Anyway, I'm not an expert mechanic, but have my father in law helping me diagnose this. We took the engine access panel off tonight (pain) and started looking at the carb. The first thing I noticed right away was that the pulsing hose? wasn't hooked to the carb well. We replaced that and got fresh tube installed. This didn't seem to help. The next thing I noticed was that on the side, there was a Low adjustment screw, but the High hole was empty. I looked into the hole as best as I could and it didn't even look tapped, so we were wondering if it really even has a High. This would be the Walbro WDB-31 carb. Is the screw on the top of the carb the High?

Anyway, I'm probably gonna look at getting a carb kit, but was just wondering if anyone could give some insight into this.

Thanks!

-beam

ps...I'm debating on whether to pick up an '81 440 trailfire. The seller says it's in great shape. Smart move, or should I just focus on what I have for now?

[400brian]

Yes, you definetly should have a high speed needle on top of the carb.
Also a rubber seal, cup, and spring. Rebuilding the carb is not a bad idea, I would recommend the genuine, full Walbro kit.

If you like the TF, and you can afford it, why not. ( no one here is going to discourage you from buying a Deere sled )