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  1. #1

    96 polaris slt 780 carb question

    recently purchased a 96 slt 780 that had the center cylinder torched in it. put a used cylinder and new pistons,gaskets through out. cleaned the any debris in the crankcase,disassembled the carbs checked and cleaned twice, cleaned & checked the fuel pump-lines-selector valve-fuel strainer etc,checked and replace the fuel pump pulse line...check and adjusted the high & low speed jets to factory specs & even richer than stock

    my concern is that these plugs still look lean & assuming this is why the ski burnt down for the previous owner. burn down was fuel related, as the center piston had a hole burnt through the top

    not new to skis or 2strokes but am new to these mukini super bn carbs and questioning how often they need rebuilt

    any comments would be appreciated
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  2. #2
    ph2ocraft's Avatar
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    Was it a hole in the center or piston side melt down? I'd be sure to check your crank index.

  3. #3
    was a hole size of a dime in the top of the piston
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  4. #4

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    I had the same problem running to lean I ended up finding another set of carbs put new diaphrams and needle and seats and that fixed the problem. it took a lot of trial and error to come up with this solution though

  5. #5
    Quote Originally Posted by deman824 View Post
    I had the same problem running to lean I ended up finding another set of carbs put new diaphrams and needle and seats and that fixed the problem. it took a lot of trial and error to come up with this solution though
    yes thats what i was assuming also, just wanted to double check as looking at the cost of carb rebuild kits i was a lil shocked, sure not cheap like snowmobiles lol.....

    everywhere i read everyone points to genuine mikuni kits and not aftermarket like jetlyne-parts unlimited---is the quality not there? seeing how they are way cheaper pry get what you pay for i assume.

    last 2 questions,
    1. anyone point out what needle size i need so i can order parts before teardown
    2. any noticable benifits of adding a set of boyseen reeds while its apart?

    thanks for any info guys...
    jm

  6. #6

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    If you are not changing anything with performance parts the internals of the carbs should remain the same if you are going for high performance then you will need to rejet and yes use only Mikuni carb kits the other will not hold up as long as the Mikuni,s As for reeds If yours are in good shape you should be ok

  7. #7
    Quote Originally Posted by deman824 View Post
    If you are not changing anything with performance parts the internals of the carbs should remain the same if you are going for high performance then you will need to rejet and yes use only Mikuni carb kits the other will not hold up as long as the Mikuni,s As for reeds If yours are in good shape you should be ok
    rebuilt the carbs with mikuni kits,back together up & running put 8hrs on it over the weekend runs like a champ

    thanks for the info

  8. #8
    She likes the bike. But the ski gets her wet!!!! xlint89's Avatar
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    Check out your piston wash periodically to keep an eye on engine condition. And to keep her running at the highest RPM possible.

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