Mercury Snowmobiles Discussion Board

Update!!!!!!!!!! I have replaced the primary coil under the flywheel and now the sled runs. I did some testing on the old coil and I checked continuity between leads that go to condensers and it was open. I checked the new one before installation and it was closed so I was very happy.

Got one sled fine tuned and is perfect now. Now to the SR 440. This sled has sat and now does not run. If I remember correctly, it started to backfire when trying to start and now will not offer any spark whatsoever. I do have a matching sled so I swithed the coils because that is easy and fast and ...

I have 2 machines with this exact motor and both read roughly 180. I think it may be normal. Neither have ever been apart and run good

Thanks much for the info. I have another merc sled that takes the same belt and it is shot so I am going to order this belt. I figured out what the problem was. It was the carb. The high speed jet was restricted and when the load of the shift was dumped on the motor there was not enough fuel to be d...

On a Walbro carb. The highspeed screw on top of the carb, Is it an adjusting screw for a air fuel mixture? or does it hold a jet or rod in placeand therefor tightened in. If it is adjusting, how many turns shoud I set it at to get it to rev high?

This may be a dumb question but here goes. On a Walbro carb, is it necessary to use new gaskets each time carb is cleaned and are they available. I am dealing with 2 sleds. A 73 SR and a MAX, both 73. I am going to disassemble and clean them. They have sat for a few years now. Also, I have heard tha...

I have a 73 440 MAX and when it shifts it bogs down . I than have to stop or almost stop before it can rev up again. I believe I have the correct belt and it is new. I can open the secondary by have by pullingand twisting and it is not that hard to open. At a stop the mptor revs and sounds god and t...

I may be interested in this machine. Please contact me, thanks, Len

I have 2 75 S/R 440 sleds. One has sat a few years now and wont run. I went through and cleaned the carbs, tank and gave it new plugs. It still just backfires when pulling it. The mice over a few years made this sled a hotel and the flywheel was the bathroom. This is why it won't run. There is a ton...