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Discussion Starter #1 (Edited)
All,
I have 2 sleds. A 1987 Yamaha Exciter 570(Late year Model - separate Mikuni Carbs NOT the large Single Mass dual Carb setup ) and a 2000 Polaris Indy Triumph (3 Carb setup). Both sleds have the plungers "chokes" (?) on the carbs. The Polaris is at 4600 orignal miles. The Yamaha is unknown miles.

Anyways both these sled once started for the day will run for hours without issue. No performance issues at any RPM. Once the engine cools (say a hour later) its difficult to start/no start scenario.

As the sleds are used rarely, probably 3 -4 times a year around my farm, I use a small 4.5 ml/g medical syringe, pop the plugs out, and give about 1.5 ml to each cylinder. Pull the starter cord and it usually either starts on first pull or stutter starts. This is a very small amount of gas. Then I usually can start it by playing with throttle and pulls. Its this way in any weather (90 (F) degrees summer and 2 (F) degrees .winter. Usually is runnning in 5 pulls or less.

Both sleds have recent rebult fuel pumps and the Polaris just got all new fuel line and a tank filter. Polaris pump, filter, and line was this year. Compression was good at last tune up and this issue has existed for years for both sleds. Since the Yamaha was purchased (Auction) and the Polaris a couple years after I bought. The Polaris I have seen start in negative 10 after being pulled in a open trailer in 3 pulls. I bought it off my buddy as he bought a newer sled.

One thing I would add is both sleds I can see the fuel making it to the carbs by a few pulls of the cord. The Polaris prior to the recent changes (fuel line, pump, filter) I could not.

Is this the Plungers giving me issue or is this something else?

Thanks
Chris
 

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Discussion Starter #3
More than likely the chokes need adjusting or pilot jets need cleaning
Thanks for the information.

I picked up a rebuild kit for the Yamaha for both Carbs. It appears from my manuals and online resources they are a set of Mikuni VM38.

The rebuild kits are not horrible nor does it look very difficult to do on the Yamaha so I will start with that setup first.. I wish I could say that about the cost of the Polaris sled redo.

As the sled has not had a carb cleaning nor a synchronization to my knowledge in a considerable amount of time I might as well go thru the whole thing.

Thanks,
Chris
 
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