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Thought I'd just start a new thread for this instead of adding to my other thread and ckeep this just for tunning. Anyway like the title says i have a 96' ultra 680 and a set of PSI pipes for it. Anyway i'm wondering what jets i need to go with (to start anyway), and if there's anything else i need to do. I'm not looking for an allout barn burner here, just need it to be a healthy running motor (its in a scrambler quad lol). In the searching i've done everything points to jetting it 3 sizes bigger (400 400 and 410 is what i've come across), but there was mention of changing a few other items, anyone have any info or links that would help me out (i've played plenty with 4bbl carbs but these little guys are somewhat new territory)?

Thanks.
 

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Toss in the bigger jets(3 to 5 sizes over stock), run wide open for 200 feet, stop and pull the plugs.

If they're wet, jet down.

If they're dry, jet up.

Repeat that till you get them to brown, then run 400 feet and check to verify that you don't need to change by a jet size.

Once you have the main jets set, run the same thing at 3/4 throttle, 1/2 throttle, and 1/4 throttle to set your pilot jets, etc.
 

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mustange70 said:
Thought I'd just start a new thread for this instead of adding to my other thread and ckeep this just for tunning. Anyway like the title says i have a 96' ultra 680 and a set of PSI pipes for it. Anyway i'm wondering what jets i need to go with (to start anyway), and if there's anything else i need to do. I'm not looking for an allout barn burner here, just need it to be a healthy running motor (its in a scrambler quad lol). In the searching i've done everything points to jetting it 3 sizes bigger (400 400 and 410 is what i've come across), but there was mention of changing a few other items, anyone have any info or links that would help me out (i've played plenty with 4bbl carbs but these little guys are somewhat new territory)?

Thanks.
Go to the forum (Polaris), then go to page two, look for the thread, Ultrariffic: started by Bakernator.
 

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I don't know if you're running in summer or winter, but PSI jetting was 400,400,410 mains and Q-0 needle jets. I think we ran 45 pilot jets in ours. That's in a sled in winter obviously.
 
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