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 jet ski carb tune 
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Joined: Thu Apr 17, 2014 11:11 am
Posts: 155
Location: Baytown, Tx
Post jet ski carb tune
ive got a 95 Polaris 750 that im working on. anyone ever tuned the carbs on a ski before? bastard has 3 mikunis on it lol. pulled em and cleaned em up now I just gotta tune it and slap it in the water.. was it a pain to get them all right?

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Mon Mar 23, 2015 9:34 am
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Joined: Mon Nov 30, 2009 10:33 pm
Posts: 51
Location: Patterson La
Post Re: jet ski carb tune
If you get it running, Sell it. Polaris has been gone for a long time, and parts can be hard to find. That said, Mikuni carbs are easy to tune. You are only working with a high, low and idle. Did you check the settings before you pulled them apart? If so, return them to where they were, and you should be good. If you aren't sure where the adjusters should be set, start at 1 turn out and go from there. They will tune like any other two stroke.

Start with the low speed adjuster (the one closest to the engine). I usually turn these in at 1/8 to 1/16 turn at a time until you get a lean idle. a lean idle will rev the engine, and it will sound like it wants to run away. After you find where it is a lean idle, turn the adjusters out until the idle speed stabilizes. then set the idle adjuster. If it idles and then dies, it is either loading up with too much fuel, too lean, or the idle setting is too low.

After you get it idling, then you can set the highs. The only real way to do this without a Hot Tach is to do WOT plug chops and look at the color of the ceramic on the tip of the plug. You are looking for a rich brown coffee color. white is lean, and black is rich.

From what I remember, this ski used an external fuel pump. either rebuild it or replace it. The check valves and diaphraghms can look fine on the inside, but it won't pump like it is supposed to, and it can cause the boat to run lean at wot.


Fri Mar 27, 2015 10:06 pm
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Joined: Mon Nov 30, 2009 10:33 pm
Posts: 51
Location: Patterson La
Post Re: jet ski carb tune
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Fri Mar 27, 2015 10:06 pm
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