What do I have?

[ELKY85]

I have been given a '91 Sea Doo GT. I was told it possibly had a bad starter. With a new, fully charged battery it will turn over with the plugs out, but not with the plugs in. Using a battery charger that has a 2amp, 10 amp and 50 amp charge cylce, and also a 125 amp start setting, if I hook up the charger at 10 amps it makes little difference. 50 amps turns it over, but stills slow. At the 125 amp start setting, it spins over good, and the plugs are firing, but it will not start. I tried checking the compression and, if I checked it right, it didn't
have any. Now when I checked compression we had removed the exhaust pipe. Would the pipe being off effect the compression? Is this thing shot? I am new to watercraft of any type. I see books for maintenance, but is there a book for dummies that just explains how they work - like where the water comes in and the path it takes?
Thanks

[Bryan Glynn]

There is no book for dummies, but this forum can be your best source of learning.

Here's your first lesson.

You may have just fried your ignition by using a booster on the ski. You should NEVER boost the battery in a PWC!

If you get less than 140 psi in each cylinder you have a blown motor and need to swap it.

[ELKY85]

Does the fact that the starter wouldnt turn over the motor indicate a bad starter. I'm trying to get an idea what all I might need other than a new motor to see if it is worth the cost to repair. I know that all four motor mounts are broken. What else might I be looking at to fix this thing, and is it worth fixing, or should I spend this money on something newer and bigger?
Thanks again.

[Bryan Glynn]

Personally I would think carefully about putting $1000+ into a ski worth a few hundred.

[ELKY85]

That's how I feel, but wanted to hear it from someone else.

Thanks

[SP]

Broken motor mounts
Bad crank
water ingestion damage to cylinders
bad impeller
bad pto due to broken motor mounts
bad wear ring

Stay Away......