Possible causes?

J

John_Ciocca

Location
Carlsbad, CA
My friend has a 93 Superjet (with 701 motor) and I have a 94….both are set up exactly the same. Scoop grate (Worx 201), ride plate (stock), wet wolf free style cone, B-pipe compression bump.............. The problem is his ski porpoises real bad.

As soon as you go past ½ throttle…it starts skipping….but my ski stays flat. It’s not the rider…..because my ski does not do it but when I ride his it is obvious. Position does not solve it.

Both hulls are in great shape with no prior damage. Since our skis are set up exactly the same with the same components…I am at a loss for what is causing this. Any ideas?
 
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K

Kennay

Squarenose for the _____
Location
Myrtle Beach, SC
Well, simply due to the nature of fiberglass, all things molded don't come out 100% the same. I bet he has a hook or something like that in his hull. Maybe yall should try truing it to see if that rids it of the problem.
 
J

John_Ciocca

Location
Carlsbad, CA
Yeah true but they are made in a mold. It seems unlikely that small variations would make such a huge difference. I have a gouge or two and some battle damage in my hull but you could never tell the difference. Truing is a good idea but I don't think that will solve this....it's like a bucking bronco past 1/2 throttle......up to 1/2 it rides perfect. i was thinking something with the pump itself....any thoughts?

JC
 
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D-Roc

D-Roc

I forgot!
Location
Dirty River Rider
how is the pump shimmed? maybe the rear shims are missing. i don't know if that would be enough. how about the foam in his ski. is it really waterlogged and causing alot more weight in the rear of the ski. i find it hard to believe that is porpoises that bad. my Sn hull had a chopped rideplate and shortened hull and i could keep it hooked up enough to finish fifth place in a race i entered. that was even against sxr's. lastly is your handpole shorter than his?
 
D

DsmRacing

Wannabe Freerider
Location
Tampa
If it were me, I would have the pump and prop checked out. I'm sure someone with way more experience will chime in. Good luck, let us know what it turns out to be.
 
J

John_Ciocca

Location
Carlsbad, CA
He just installed footholds and I don't think his foam is waterlogged. My foam however (on the ski that rides good) is water logged. I know this because i can see a lot of water continously running from the firewall. So i find it hard to believe. If that is the case maybe we could try 10 lbs under the tank to compensate and see if it improves.

He even installed Watcon's pivot cam to angle the nozzle down. That helped a bit but it still porpoised.......it sucks...he put a lot of work into building this thing and I want this to work out for him. Would shimming the pump down (via the rear bolts) help more than the pivot cam?

JC
 
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Cliff

Cliff

Location
Hokesbluff,al
a kawi will do that if you dont put silicone back around the pumphousing after its been out but not that bad. maybe a broke motor mount but doubt it
 
Crab

Crab

thanks darin...noswad!
Location
Seattle
Same prop? If either rideplate is bent up at the back that will cause that problem.
 
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