Is this stock 650 prop bad?

I'm not a Kawasaki guy, but I'm trying to learn and I'm helping a friend out with his ski. When we took this really nice and clean 650 Kawasaki out that he recently picked up, it would just barely spit any water out of the pisser and the ski would barely move. Bubbles would come out of the jet drive and it felt like a clutch badly slipping in a car. Compression is fine, we blew out all the cooling lines, it runs very strong, and nothing in the driveline is stripped. We took the pump off (and pulled a bunch of yellow nylon rope out that was wrapped around the driveshaft) and found the prop to be in pretty bad shape. Could this be causing the ski to barely move in the water causing extreme cavitation?
 

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The rope was the problem. The stock impeller doesn't work very well when compared to others. I see rust in the splines, this will destroy them if theyre not already. If the ski is a keeper, get a modern 750-800 impeller cut for a 650 pump and use a 750 ss/xi driveshaft. Of the old 650 impellers, the Solas 13-18 stands out along with Skat 15, 13-16, and 14-17. Any more pitch tends to hurt acceleration. I recently tested a small hub 750 11-16 Concord on a "limited" 650sx. It tachs the same (6600) as the old KA-SC-A 13-18 and primes noticeably better. Have not tried a large hub yet.
 
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Thanks for the help, guys. We found a used Skat 16 prop for it at a good price, so that will be replacing the worn out stock prop. After reading all the posts out there, I think that will be decent for all around use. We'll get it on there and see how it works, and if we have to have it re-pitched for more acceleration, we'll send it to Impros.
 
Thanks for the help, guys. We found a used Skat 16 prop for it at a good price, so that will be replacing the worn out stock prop. After reading all the posts out there, I think that will be decent for all around use. We'll get it on there and see how it works, and if we have to have it re-pitched for more acceleration, we'll send it to Impros.

The Skat 16 degree impeller is one of those parts you find on a shelf, instead
of in a ski, because it is a pos.

The original owner puts what doesn't work on a shelf until someone else thinks
it is a good idea to sell that perfectly good "shelf part." I could make some money!

Who cares if it a good or bad investment. These sellers can be newbies or people
that don't care. I have a 16 on a shelf and I wouldn't sell it to anyone. The same
could be said for ported cylinders.

Bill M.

If the engine is totally stock, it will perform ok, but it can be a real problem for
a pipe and carb. It is the first of 3 generations of Skat impellers that tried to get it
right. The 3rd gen Skat 8/16 did the job.


Do you need instructions on resealing the pump?
 

Big Kahuna

Administrator
Location
Tuscaloosa, AL
Skat 16 works just find on a built 650 motor. I stuck a 16 on my first X2 when it was stock and yes, it was not the greatest, better than the stock one though. Once I ported it, added dual 38's, Westcoast Pipe, It ripped all the way to the rev limiter.......
 
He just wanted something that was better than his chewed up stock prop, so if it's better than the stock one, that's all he needed.

Are there any special instructions on sealing the pump back up, or just use some good 3M marine silicone and we're good?
 
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He got the prop for almost half of what most of them were selling for on ebay, so a repitch from Impros would always be a good option. It's going on his TS650, which is just a ski to putt around with, let his kids use, or tow one of our machines back to the dock if we break something.
 
It's being shipped now, so when it gets here we'll give it a try. Anything should be better than that crappy cast aluminum stock prop that was all chewed up and bent up.
 
You will need a good quality clear silicone, not ultra silicone or silicone based caulking.
If you are using a 3oz. tube from your local auto parts store, plan on using the whole tube.
I prefer to use 11oz. cartridge and gun.

You will also need WD-40, a black sharpie, a roll of paper towels, nitrile gloves. I preferred
to roll a ski upside down and work from the top, but since it is a TS, find something comfortable
that you can lay on and won't mind getting some silicone stuck to it.

NOTE: Make sure the drive shaft is engaged with the engine. Sometimes the drive shaft
will come disconnected from the rubber coupler. It may be more difficult to install at
the last minute.

1) Remove all the old silicone from the hull and pump.

2) Temporarily mount the pump with 1 or 2 bolts and draw a line with the black sharpie
along the outline of the pump. Remove the pump.

3) Apply a 1/2" bead of silicone ~3/8" before the black line.

4) Apply a 1/2" bead of silicone over the top 180 deg of the pump, close to the edge.

5) Install the pump, pull the pump downwards as you slide it forward, and try to overlap
some of the silicone as you are installing it.

6) Add a dab of silicone to the side of each of the pump mounting bolts, and then tighten
down the pump.

7) (a messy step if you are upside down). Take the WD-40 and spray it over the silicone,
the impeller, driveshaft, pump gullet (hull). The goal here is to not allow the silicone you
are about to remove to adhere itself to anything new, as you remove the excess.

The silicone is already attached to all the surfaces it needs to seal the pump.

8) Remove the excess silicone. I like using my fore finger bent 90 deg to remove the
excess. But a credit card would also work. Create a smooth fillet between the pump
and hull. Do Not remove the extra silicone between the pump and hull with the tip
of your finger.

During this step, you will use a lot of paper towels. I would usually blend a few inches,
pull my hand out, and wipe it off, and continue.

NOTE: The reason why I use so much silicone is that silicone shrinks when it dries. Some
silicone's are worse than others. But it used to be common place for silicone to dry
and pull away from the pump.

9) Let the pump dry for 24 hours before you put it in the water.

10) Do not silicone the ride plate to the hull.

Note: Some Skat Trak impellers still have a thick o-ring at the top of the impeller. If
it is still there, I recommend that you leave it off. The o-ring will make it very difficult to
install the pump.

So will too much grease on the splines, if you use too much grease the driveshaft will
"hydro lock" and prevent the pump from lining up with the pump mounting bolts.

SOMETHING EXTRA:
The TS does not steer straight when the handle bars are pointed straight ahead. This can
be fixed by using a 5mm bottoming tap on the brass ends of the steering cable. (Remove
the ride plate) But getting to the top steering cable may be difficult. Screw the top brass
cable end in till it bottoms and tighten the jam nut. Have someone hold the handle bar
straight, and make any final adjustments on the steering nozzle.

(It may be easier to just retap the pump end of the steering cable first, and evaluate).



Bill M.


Once I ported it, added dual 38's, Westcoast Pipe, It ripped all the way to the rev limiter.......

Maybe on Earth X.

Unlike Yamaha's, Kawasaki rev limiters hit at 8,000rpm, and the 1986 X2 had no rev limiter.
 
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The TS is the Kawasaki water taxi. They carry the ice chest and awning too
and from the daily hangout, and they are also the thrasher ski you can let
anyone ride.

The most important maintenance feature (with any watercraft) is that it
starts reliably every time.

If you need any help with the stock carb, let me know.


Bill M.
 
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