I need some help from the 680 experts out the in HCS. I toasted 2 pistons and 1 cylinder last year. Come to find out the carbs have the wrong needle and jet needle and slides in it for the dynoport pipes I have on the sled. Please correct me if Im wrong. My research shows I need 3.0 slides. P-6 jet needles but I dont know what needles. The biggest problem is where to find what I need. If anyone can give me a name and number.... that would be sweet.
I ran DP pipes on my 96 Ultra, but used Boswell moded TMX flatslide carbs, so can't provide exact DP jetting for stock roundslide carbs.
The stock jetting on the 96 Ultra with single pipe was 340 mains, 50 pilots, 1 turn on idle air screws, P-4 (247 series) needle jet, 6DH8-2(#2 slot) needle, 2.0 slide.
The jetting on the 97 triple pipe Ultra SPX was 380 mains, 50 pilots, 1 turn air screws, Q-2 (247 series) needle jet, 6CEY6-4 (#4 slot) needle, 3.0 slide.
This setup might be a good starting place for the DP pipes. But, I'd go up on mains to around 410,420,410.
The biggest problem with the 96 Ultra was the CDI. It had too much midrange timing: 26/16 deg @3500/8000 rpm for pump fuel, even 93 octane. The fix was to lower stator timing about 2 degrees. Or, use the SPX CDI: 17/18 @ 3500/8000.
I can't remember the jetting as i used 38mm mikuni tmx carbs with dynoport pipes with v-force reeds but do remember having to lower the timing at the stator 2 degrees. Lot of mid-range detonation stock. Nearly lost a piston before doing that.
Sounds like mikuni tmx flatslide carbs are the way togo... should I still put on a 1997 ultra spx cdi box to help with midrange timing. I have never messed with a cdi yet. Could I reprogram mine and if so where?
Bought the tmx carbs used, they originally came from aaen. Never had an issue with the cdi on my 96 ultra once the timing was set back at the stator. Had over 4,000 trouble free miles.
I know you guys know this zip inside and out... so bare with me. Im getting a 97 spx cdi box 3025292. This should retard the timing at mid range to prevent detonation. Now doing this do I stick with 96 JN and NJet or find a 97 SPX JN and Njet.I have dynoport pipes on sled.I will call dynoport, but I still think your experience is key to a good set up.
I'd use 97 SPX parts for carbs, including 3.0 slides. Better yet, find a complete set of SPX carbs. I believe that the idle transfer passage is larger.
It amazes me how the polaris gurus on HCS know every little thing about every ole triple out there. I am calling dynoport. But I still VALUE the knowledge U guys have. Every post u reply to gives me more know how and confidence to work on my sleds. I am 42 yrs old. I never touched a sled til 3 yrs ago. I thank all of U who helps me. I just aquired my 7th sled. A beat up ole 2000 xcr 800!! $850.00. Talk to ya later patrioticsinovations!!! Keep up the good help!!
Catskill Mnt. King 3 x 8
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