95 XP800 Driveshaft question

[IDoSeaDoo]

Hey gang, I am FINALLY starting the restoration/build of my 95xp800. I've been meaning to do this for 8 years. Got all kinds of goodies for this thing like Novi carbs, Factory Pipe, MSD, W injection etc. This ski has the pump extension still, and the guy sold it to me with an extra SkatTrak impeller (17/21). The funny thing is, the impeller is LONGER than an average 140mm pump impeller. When I bolt it into the pump, it sticks out an extra few inches instead of being flush as usual. I believe it's meant to go with the extended pump. My question is if that IS the case, will I need a different driveshaft? The engine hasn't been assembled yet, so I can't really tell. Does anyone have experience with long impellers?

 

[Thitoff_XP720]

Yes you will need a longer drive shaft. That ski came stock with the pump extension that includes a longer drive shaft. Your prop does stick out into the pump extension. The bolts coming out of the back of the ski are extra long on that ski due to the pump extension.

 

[IDoSeaDoo]

Well, I've run this ski before with a regular prop that DOESN'T stick out. I used a stock 95xp800 driveshaft (until it bent). I've since bought another one, but wonder if it'll work with teh longer prop.

 

[R-u-n2it]

What's the number on the impellor ? Not the pitch number. Look at my avatar, have had this ski since 97 and have done everything possible to it, learned there is no such thing as "pump gas domes" when you have a spec II Factory pipe. Case ported, recut early RV valve blah blah... I had to have the guy who made Fishetti's titanium drive shaft for his XP make me 1, expensive then. I would twist a brand new OEM shaft just from the pump unloading coming out of the water and then reloading under full throttle. When it just has a little runout it doesn't rev, absolutely true and it "zings". If your ski makes power close to what my ski does you will want a Solas "X" prop if all you want to do is short course and drag race, that's what I had until I got the RPM hitting 7800+ then went to a Solas "XO", same series that fits any 785 X4 hull. Your pump the aluminum & brass? Your through hull driveshaft seal assembly the aluminum housing conventional bearing and 2 double lip seals (not the carbon ring bearing). Your hull have the maroon color on the back below rubrail? Oh yeah, stepped seat, the 1 you sit so low your legs get a workout just standing up? These modded will turn so quick and fast it will fling you off, I built the seat up 6 inches so I could hook my leg to keep me and the ski going the same direction. Everyone that tries the go fast and do a squared off corner get's flung off. Jerry Whelchel (Google if you never heard of him) rode it and said fastest accelerating thing he had ever been on. Obviously he has never ridden a full mod current state of the art World tour Seadoo or Yamaha etc. Just getting you ready for the "holy crap" 1st ride. If it doesn't "launch" immediately out of the hole and be 7500 rpm in the distance of the shore to island at Body Beach Havasu case porting and 12-13 lbs pop-off should do it. I'm guessing your NOVI are 46mm, the OEM case ports are around 40 if I remember right so carbs get muted signal, dampened from restriction. OEM case ports are 2 rounded end ovals, mine are shaped like a big bow tie. Oh yeah, and get your squish down to .039 to .043, both sides the same. I can show you how to get your cylinders & domes to be symmetrical, evenly centered so squish is the same on each side of each cylinder, as close as possible at least. Dude, sorry for the term paper, I just know what's ahead for you if you get all the links the same, ride all day just stop and go (go means haul ass). OK, gotta finish loading up for Havasu. Lee

 

[Matt Braley]

Skat makes "long nose" impellers but they are usually for the "set back" pumps they make. These keep you from needing the custom drive shaft that is 1 1/4" longer Most of them have the bigger hub like a RFI pump though.

 

[IDoSeaDoo]

Matt: yea, I think this may be one of those props for the Skat pump. Damn... I don't have one. I don't think I can run this with the regular hub pumps that I have. I know those custom pumps are pricey and I don't have the cash at the moment to drop on that sort of part.

Lee: thanks for all the great info. Yes, it's a true 95 xp800 with the red gel-coat on the bottom back half. It does have the old-school driveshaft seal, which I think is way better than the carbon ring setup. I always hated those, I'd rather just keep this one greased and not worry about leaks or cavitation.
I believe my Novi's are true 41mm, but I haven't checked in years. They look stock, but have the Novi bomb sights, and def have wider throat. I have a Spec I factory pipe, and a PSI head, which has adjustable domes. I was thinking of adjusting squish to .04 at the lowest setting so I can back it off later if I wanted to. I got it pretty cheap if it ends up not working out. I'm hoping to be able to stick with pump gas as I have no idea where to get race fuel. Besides, I really want to ride this thing alot and not spend that much money on fuel. I have case porting templates, but havent built up the courage to try them out. They're by an old company called "Sport Port". Magnetic templates you stick on and mark where you port, then take off.
I'm wondering what jets I should use for starters on this setup. I will have R&D intake, those wide NOVI carbs, Factory Pipe Spc I, 97 SPX water box (hard jetted). Also, what size jet should I use on the water box?
I will probably get the Solas X prop. Not sure what kind of power this thing will be beuilding, but I hope I can stick with stock or SBT shafts.
I'm getting ready to reupholster the seat and have some high density foam. Should I build it up? I see lots of these x4's with taller seats. Right now it has the hump seat, but I'm not sure it'll be good for me, as I'm pretty tall and used to sit right where that hump is... I plan to do a lot of wave and yacht wake jumping here in Miami. The waves are massive compared to the lakes I used to ride back i NC. I also like to cruise around on these x4's. I plan to put in the 12gal fuel tank from a GTI that I already have to increase my range.

 

[R-u-n2it]

IDO, when I said there is no such thing as pump gas domes, this was said to me by Kevin Cameron (Factory Pipe LLC) and Andrew Buck (Buckshot Racing), after I bought "pump gas domes" at the World Finals, installed them and within an hour detonated the engine Dooing the buoys at Body Beach. They both said a minimum of 1 gal Race (and that's C-12) and 2 Gal pump premium. New top end and 50/50 ever since and been riding this ski since 1997. On the carbs I tried replacing the Buckshot 46 Mikunis with the billet carb setup from Buckshot, they have the bombsight venturi, big disappointment, no launch regardless of jetting or tuning. Some on the world tour used Novi but 90% used Mikuni according to Andrew. And your case port magnetic templet will have a hard time sticking to aluminum unless they're for the cylinders. Building the seat up has 3 benefits, helps you stay on it when cornering hard and it doesn't get as big of a running start to hit you in the ass when standing and going fast over chop/waves, and your legs don't get as tired from doing deep squats every time you stand up. Don't forget about FP and "pump gas domes" unless you want to spend money needlessly and hear me say "I told you so". A short explanation of what happens for those not aware of detonation, heat, compression, AKI of fuel (Anti Knock Index, AKA octane) is the recipe, fue/air will auto ignite ahead of flame front, it explodes and blows the boundary layer of fuel away from piston crown and heat is transferred directly into piston instead of out the exhaust port. That's why exhaust gas temps go down when there's deto, I confirmed this with my RacePak that records the last 6 min of data, ex gas temp and rpms. That heat transfer will seize your engine before you have a chance to feel it slowing, the iconic "BRAAAAP" then silence. Top of piston, if it's still there and not hammered from wrist pin needles and cage looks like it's been blasted with aluminum oxide instead of glass beads. Forget "octane boost" unless you still put a tooth under your pillow, it slows the burn to protect the engine but powerloss like a low compression tired ski. Lee

 

[IDoSeaDoo]

So even my Spec I factory pipe will need race gas? I specifically bought it instead of the Spec II so I could run pump gas... I bought ProX pistons that I'd rather not destroy right away. Are you saying I should switch to Rissier or even stock if I want to run pump gas? I don't even know where to buy C-12. It sounds expensive....

 

[R-u-n2it]

Excerpts from Factory Pipe installation instructions for the Spec 1. Note the octane rating is for completely stock engines with aftermarket flame arrestors only. And pump octane has a cheat factor, the Research number has no bearing on power, it tests the idling performance (for emissions) over long periods, Motor octane is the important number. so ARCO uses high Research component (less expensive) and a lower Motor component for R+M/2 to reach the AKI Octane. All you AMPM users---> check you miles per tank and $ per gal, do the same with Chevron or equiv. Compare cost for miles traveled. Ever notice the recent propaganda at ARCO? This is a top tier fuel.... top tier liars.... anyways. Lee

These carburetor recommendations are for 730 feet above sea level on a completely stock
engine. All of our testing was performed on a stock engine with aftermarket flame
arrestors. No claims are made by Factory Pipe for the performance, reliability or function
of this exhaust system on a modified engine.
2. You must run fuel with a minimum octane rating of 92 (premium pump fuel). Running a
lower octane fuel can cause detonation and serious engine damage.