1990 Sea Doo confusion

[dphife]

Ok here it goes. I have had this ski for about a month now and have been trying to figure out why the starter is having so much trouble turning the motor. When the plugs are in and it has compression, the motor barely turns then speeds up for a quarter turn then comes to a halt and the solenoid starts to click. Sometimes it might get 2 to 3 turns then stop. But really rough while attempting to turn it. I then took the plugs out and it will turn freely for a min or two then slows down (but keeps turning). I have taken the covers off to reveal the piston heads and everything looks clean and all good inside. I turn it by hand with the covers off and it gets a little tuff when the piston towards the back is about to be all the way down. Also a little resistance when the pistons are even with each other. I know its not the starter cause i brought it to a shop where they service only starters and alternators. They gave it back to me saying that it looks great and that it was fine. So for the past week I have been putting a little oil in the cylinders letting it soak and then turning the engine over and over by hand. I think i feel a little difference but i don't know. I have never worked on a ski before but have been reading asking questions and learning all about this thing. I seem to be stuck. Can somebody please help me?? I have posted in the past and I would like to thank all the help everyone has given me so far. I didnt pay much for this ski so i dont plan on putting much money into it but I would LOVE to get this thing running! I appreciate any kind of suggestions that would at least get me back to working on it, instead of staring at the motor and scratching my head.


Thanks
Dave

 

[timmyboy76]

hey chief, with cylinder head on, put 2-screwdrivers down plug hole, then turn pto by hand, counterclockwise. If at anytime, the screwdrivers move same direction, then, you have a bent crank. Just one possible sinerio...(with plugs out, there should be no obstruction/force needed to turn pto...:cheers:

 

[dphife]

Thanks i will try that

Here's a pic of the pistons from above. Also i noticed when the piston is uncovering the intakes, it makes a suction noise. Almost like a light compression. I figured that this was to suck the gas and air in from the carbs.

 

[Nate Surveyor]

Could just be a weak starter. Or weak battery. Remember NOT to have a charger hooked to it, while on the Sea Doo. Overvolts the electrical system... um... this is a 1990? So it does not have the same mpem system as mine, so that might not apply... maybe somebody else will speak up on that. To be safe for now, do not have the HOST motor running, if you jump it off.

Anyway, since you removed the heads, turn it over slowly, and watch for the bent crankshaft. (I am not insinuating that it is bent, just that now is a good time to take a look)

Voltage check that battery, and you can also take the starter off, and take it to most auto parts places, and they can check it.

Sea doo starters are prone to fail, due to water, electricity, and junk in the water. (faster than say motorcycle starters).

You may have a good motor, and poor batt/starter.

Nate

 

[Dennis]

Hard To Turn

There is also the possibility that the problem has nothing to do with the engine. The problem could be the jet pump. It is direct drive from the engine and if it is hard to turn then the engine will be hard to turn. You'll have to pull the pump to find out.
DAWG

 

[dphife]

Well i havent had time to check for the bent shaft yet, but once i get home from work i will check it. the battery it came with is dead so i have been using my car battery to jump it. I do not start the car or run it while jumping. Also I hook straight from the car battery to the ski's positive and negative wires. I dont have the ski battery in line at all when i am trying to turn it. Also the electrical in this ski is very basic. Mostly just contacts and relays. Nothing fancy I think.

 

[dphife]

I was tryin to keep from pulling the pump out. I looked at the impeller from the bottom of the ski while my wife turned it and it looked ok from that point of view, but you could be right. Maybe a bad bearing or something. Thanks for the advice.

Im goin to get on it tonight and let yall know as soon as i find out. I appreciate all the help!

 

[89SEAPOO]

Good luck with your ski, I was using jumper cables directly to a car battery as well and mine turns over great this way.