97 SPX won't start, only turn 1/4 @ most

[TxSwimDad]

Ouch. I am diagnosing my 97 spx (787) problem.
here's what I know:

-It was running fine last time out (weekend before)

-Only Seadoo oil ever used
-Went to start it the next weekend and it only barely cranked for a second, sudden stops
-Looked into hull, can see shaft turn about 1/4 turn
-Removed spark plugs and it cranks fine
-Removed head(s) & cranks pretty smoothly
-Manually pushed pistons up & down (can't hear/see anything suspicious, how would a sloppy rod show up in this exercise?)
-Reinstalled head w/o plugs, it cranks fine
-Put original plugs back in, it only turns 1/4 turn by looking at the output shaft.

My thoughts right now are:
-Maybe a weak starter? Probably wishful thinking.
-Worn connecting rod making the pivot now an extreme angle and the started will not over come handle the tension created? (not modified) That would mean rod & maybe crank time I suppose.

I'm open to solutions. If I can confirm rod/crank issues, do I just go the SBT standard or the premium engine? I don't want a serious hot rod, though a performance rod & crank is not out of the question. I have young teens that sometimes take it out.


Is there anything else I can do to further diagnose this issue?

Thx to all,
TxSwim Dad in Austin

[1fastski.com]

Re: 97 SPX won't start, only turn 1/4 @ most

try turning the engine by hand with the plugs in ,, it sounds like a bad starter ot ground to me .

[Archangel6]

Re: 97 SPX won't start, only turn 1/4 @ most

Low battery?

[Johnnylaw]

Re: 97 SPX won't start, only turn 1/4 @ most

It may also be a problem with your pump. Is it clear? It could also be an internal bearing in the pump. Try tuning the engine over by hand as suggested above. If you can, look at battery/ starter/ ground. If you can't turn it I would check the pump to make sure that isn't the problem.

And keep the teens off your ski. I have three and they always seem to break something. LOL

[Bill O'Neal2]

Re: 97 SPX won't start, only turn 1/4 @ most

I really doubt your rod theory. No way it could be the angle of the dangle of a rod ! If anything, a rod bearing that came apart would get stuck between the crankshaft and the case and the crankshaft would no longer turn 360 degrees.

First I would try a brand new battery. Many times I have jumped to conclusions and replaced a starter and or solenoid, just to find out all I needed was a new battery. And that usually happened when someone told me " The battery is new".
While in there, inspect your ground cable to the starter mount. They get corroded up inside of the sheath, or crack on the terminal and make a poor connection right before they break off completely.

Sea Doo's eat solenoids. Sometimes they work just enough to kick the stater motor right before they take a dump.

Last but not least is the starter motor. If it is an aftermarket starter motor, I would expect it to not work correctly for very long. In a 787 motor, they usually last from a week to about a month if you use the ski often. An OEM starter motor is the only way to go ( in fact, I have installed my last aftermarket starter motor after this season, as 4 out of the last 4 have failed on me this year, and I had to buy new oem starter motors and install them at no cost to my customers, and I have yet to recoup one dime from the starter company or the wholesaler who sold them to me, as everybody passes the buck). None of them lasted three outings. One was a 550 Kawasaki, the other three were in early model Sea Doo 587, 657 engines. None of which are all that hard on starter motors like a 787 is.