Stripped a Driveshaft...

jap7t8

Spring Fever...
Location
St. Louis
Last Saturday I put my 650 sj in at the ramp, rode easily around a rock wall to beach it and think I picked something up in the intake. Immediately got off and stuck my hand in both sides of the pump to see what it was. Didn't come up with anything. Started it back up, it idled fine and got on plane with no problem. After about 1/2 throttle, it would start to cavitate and buck like no other. While bringing it back in under a slow idle, I lost drive. Come to find out the prop backed itself off the shaft, got stuck in the housing, and chewed the hell outta the driveshaft threads.

My question is, with reverse threads on the driveshaft, shouldn't the prop try to tighten itself in the event that something got stuck in there? I never found any evidence at all of something being stuck or bounced up there. I am at a complete loss as to how it happened.

Going to pick up a driveshaft tomorrow night. My stainless prop is still in good shape so I want to re-use it.

Oh, and then I got :):):):) on by a bird in the parking lot. It was a bad day...
 
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Location
dfw
The power impulses from the engine are in frequency with the pump at idle. This has to do with the driveshaft and coupler flexing between the engine and prop. Thats why its important to tighten the prop correctly.
 

jap7t8

Spring Fever...
Location
St. Louis
Gotcha. So it was a tightening issue? I haven't touched the prop since I got the ski over a year ago. Any ideas on how to tighten a prop if I don't have a spline tool??
 

Matt_E

steals hub caps from cars
Site Supporter
Location
at peace
The power impulses from the engine are in frequency with the pump at idle.

How did you find this out?
Btw, what idle speed?


Any ideas on how to tighten a prop if I don't have a spline tool??

You could use an old midshaft. The correct way, however, is to buy the $15 spline tool.
 
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Matt_E

steals hub caps from cars
Site Supporter
Location
at peace
$15 is it huh? Any recommendation as to where to get one from? Appreciate the help!

A local friend would be best.
Short of that, try a shop close to you. Atlantic Jetsports, Wammer, Thrust, Legdrag, etc.
 
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