PWC Tips

BigBoatinOkie

Senior Chief Petty Officer
Joined
May 28, 2009
Messages
763
I just acquired a 96 Seadoo SPX 720. This is my first PWC and I'm looking for any advice or tips. I am a boat owner and do all my maintenance and I'm pretty mechanically inclined. I know my way around Mercruiser engines and sterndrives, but I have no experience with two-strokes, jet drives, oil injection, etc. I bought this thing without doing a test ride, so I wanted to get advice on what I should be sure to check out before I hit the water. Any advice would be greatly appreciated. I'd like to hit the water this weekend, but I want to make sure I have a seaworthy craft. Thanks. :)
 

H20Rat

Vice Admiral
Joined
Mar 8, 2009
Messages
5,203
Re: PWC Tips

couple things to check out... is it still actually using oil injection? Don't assume it is, that would be an expensive mistake if you dump regular gas in and it isn't.

Also, what color fuel lines does it have? If they are grey, replace ASAP!
 

bently

Petty Officer 1st Class
Joined
May 24, 2009
Messages
202
Re: PWC Tips

Check the jet pump bearings, drain the water if it gets into the cone. You could do a wet bearing upgrade, by removing the bearing side covers and fill cone with lower case outboard oil. It will add a mph or two.
 

BigBoatinOkie

Senior Chief Petty Officer
Joined
May 28, 2009
Messages
763
Re: PWC Tips

Thanks guys. So is it common practice and/or recommended to block off the oil injection system and pre mix the oil/gas? I guess it uses an injection pump? I just got this thing less than 24 hrs ago, so I'm pretty ignorant at the moment. Are the pump bearings prone to failure? What kind of injection oil or pre-mix oil should I use.
 

95WellcraftJax

Recruit
Joined
Jul 5, 2010
Messages
3
Re: PWC Tips

I have a 98 GTI and my oil injection works just fine still. I use the Sea Doo brand injection oil (standard, not synthetic) but you may be able to find something equivalent. Check the fuel filter and see what gunk might be in there (should be under the front cowl, near the fuel valve), check the oil level in the rear pump bearing as the other posts mentioned. Check the steering cable and throttle cable to make sure they don't bind and aren't frayed. Use a flashlight and visually inspect the impeller from the rear and from underneath to make sure it isn't dinged up. I'm assuming your ski has a built in flush fitting as most Sea Doos do. Run it on the hose to make sure you don't have any water leaks or exhaust leaks. Be sure to start it first before turning on the water, or you can actually put water in the engine. PWCs don't have an impeller like regular boats so you won't hurt anything running it for a couple seconds without water. See if you can download the original user's manual for this ski and it will help you further.
 

BigBoatinOkie

Senior Chief Petty Officer
Joined
May 28, 2009
Messages
763
Re: PWC Tips

Thanks for the tips. I actually took the ski out to the lake this weekend to try her out. She busted right off and I puttered around close to the ramp for a few minutes just to be safe. After I felt comfortable that she was going to run, I took off out to the big water. The plan was for me to meet the rest of my family at a little beach about a mile away, so I headed there. Well....I got right out in the middle of the big water and a pretty good sized boat crossed in front of me. There were two pretty big wakes coming so I slowed down and then gunned it on the first wake so maybe I would clear the second wake. I landed pretty hard, but not so hard it hurt, and the ski just bogged down and died, then it wouldn't even turn over, just a click when I hit the starter button.:( I brought my phone in a plastic bag for just such an occasion, called dad and he towed me to the beach with his boat. I figured out what caused the bogging. The little rod that connects the two carb linkages fell off. No big deal, but the engine wont even turn over. Took the plugs out and tried to roll the engine by hand. Stuck, oh crap! Thought the engine was seized so I stuck a dowell rod down the spark plug hole and tapped on a piston to try to free it up. Gave it a few taps and sure enough, it all freed up and the engine turned easily and smoothly by hand. I hit the starter again and something got in a bind again. Hmm. I decided to check out the starter, so I took it off and the engine turned freely again. Guess that was the culprit. I hooked the starter up to jumper cables and the bendix would jump out and stay out, it would not retract on it's own unless I tapped on it. Guess I'll need a new starter. Anywho, that's how the maiden voyage went. Seems wierd to have two unrelated problems pop up at the same time. Maybe I'll have it fixed in a couple days and give it another try. Pardon the long windedness.

P.S. It ran like a scalded dog before it crapped out. :D
 
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