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  1. #1
    javiert99's Avatar
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    FP Spec 1 - Carb Tuning starting point?

    Got a Spec 1 on the way, and was wondering where to start with tuning. Just confirmed my ski is all 1996 internals, carbs, electrical, and pump (including carbs, I know someone made mention of issues with 95 carbs here, but the only thing 95 on my ski is the hull)

    My current carb setup is per Steach's recommendation:

    Highs: Stock 142.5 7/8 turn
    Lows: 75 (bumped up some for FA's) 1 turn

    Pop-off: N/S 1.5 80gram spring: 34#

    Factory pipe only has a suggestion of upping the main jets... but they are 700' above sea level, whereas I am at sea level. Here is their recommendation:

    Main jet : 150 on front (Mag)carb, 152.5 on rear (PTO) carb
    Pilot Jet : 70 (stock)
    High speed screw : 1/2 turns out from closed on front(Mag) carb, 1 turn out on rear (PTO) carb
    Low speed screw : 1 ½ turns out from closed
    Needle & Seat : 1.5 (stock)
    Spring : 65 gram (stock) I thought stock was 95gram

    I was thinking of going with their Main recommendations, keeping my 75 Pilots in there at 1 turn, and using the 65 gram spring to bring pop off to about 30# w/ my 1.5 n/s.

    Sound like a good start? I'll mess w/ the ecwi after I receive it and see what I have to work with (am receiving the MT ecwi/rev limiter combo unit with solenoid)
    Last edited by javiert99; 11-28-2006 at 10:40 PM.


  2. #2
    96XPSS's Avatar
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    What other mods are you running? What prop/nozzles/grate, any other engine mods...etc?

    All this will influence what jetting you run. Let me know what you have and we'll go from there.

  3. #3
    javiert99's Avatar
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    Right now I put my stock intake grate back on.. I was running a Solas grate but I'm on the lookout for a Worx.

    Stock prop, stock nozzles... only mod are my Vilder flame arrestors. Compression is 160 across both cylinders.

    I want: Worx grate & R&D 82/85 nozzles at some point

    Thanks

  4. #4
    96XPSS's Avatar
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    FP's suggested jetting is for a completely stock boat. I would do your current pilots and 155 mains, starting at 1 turn out. Do a quick plug chop immediately on your first wot pass. A good mixture is chocolate brown on the ceramic. If it's gray you are lean and about to seize it.

    On the nozzles...85/88 is best...unless you are going to underprop the boat with a 16/24 swirl and bump the compression. Mine runs 67 with a Solas XO/85/88 @ 7550, no grate, and wedge. Rossier pipe though.

  5. #5
    javiert99's Avatar
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    Oops, I meant the 85/88!! I've seen the 82/85 out there but I know that's not the one to go with in my case.

    67 mph is very impressive, is there any more to your ski than what you listed? Compression bumped any? Carbs?

    I'd be happy to crack 61-62 lol

  6. #6
    96XPSS's Avatar
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    He he! It's pretty tricked. I have a PPG level 1 head mill...185+ lbs. compression. The pipe and exhaust manifold is hand ported by myself. The cylinders are current GK ported rec finish. MSD 4255 Enhancer, MSD water injection. Losing the grate and installing a wedge is good for 2 mph.

  7. #7
    javiert99's Avatar
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    Quote Originally Posted by 96XPSS View Post
    Losing the grate and installing a wedge is good for 2 mph.
    wow

    Where do you find 'doo wedges? Back in my Polaris days I heard all about them, but not with the doo's.

    Man sounds like you have a really nice setup

    I'll take some of your hints and hopefully crack a nice 62 mph pass soon

  8. #8
    Water4fire's Avatar
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    RQ helped me with my 96xp. I run a hard 64 mph all the time.

    He knows his boats. I went with the 155mains as I was setup real lean from another company and he noticed it wright away and kept me from siezing it.

    .

  9. #9
    96XPSS's Avatar
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    Thanks Austin! Oh...I have Novi 42 carbs...which is the stock 38's bored with Novi's atomizer. I also hand taper-ported the stock intake to accomodate the larger diameter carbs. The side facing the rotary valve remains stock. Oil injection holes are aluminum dowell-filled so there is no disruption on intake flow.

    I'm freshening up the top end. The new pistons will be SD once-overs, but ceramic coated on the top and graphite on the sides. Hope to hit 69 with the new slugs.

  10. #10

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    Man I miss my old 95xp 800. Had it running 65mph+ with stock carbs and no porting. I've been thinking about getting another one.

    Mine had- spec2,
    175lbs compression
    untouched X0
    85/88 nozzles
    no grate and a pump wedge (thanks 96XPSS)
    stock carbs (155mains) with prok flame arrestors

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