RESTO 1998 Speedster in MA

[ZeusDad]

Whilst continuing my obsession with seadoos, I found a 98 speedster for sale in the town I work in. It actually wasn’t for sale until I stopped the owner in his driveway and asked him about it...

it looked as if it was sitting in the woods for a while, and I asked what his plans were with it. He explained that he was coming across a local lake early last year and one of the motors suddenly died on him and he couldn’t get it restarted. He thought one of the motors was already replaced with a jet ski 787 prior to his ownership. It appears the boat may have come out of Vermont (trailer inspection sticker). He told me he had thought about selling it. He told me he’d like to get a $1000 for it and I asked if I could come look at it closer another day, which he was fine with.

i came a day or two later and looked over the boat. Everything appeared to be there (seats, cooler/tool bucket, gauges, etc) except the arm rest for the driver seat and anchor light and I gave him the $1000. I picked it up a day later.

brought it home a day later and began cleaning. A gallon of fabuloso, a gallon of simple green, a 5pack of magic erasers, and 4 cans of engine bright later, My girlfriend and I got it mostly clean. Literally about 5hrs of powerwashing. Trying to figure out what was clogging all the drain holes was fun too. It was dirty and neglected. Pics to follow

 

[ZeusDad]

After cleaning, I began looking at the motors...

The starboard motors starts and runs with what appears to be no issues. The port side motor (the one that was replaced with jet ski 787) didn’t turn over at all. I pulled plugs and got a ton of grey mud out of the pto cylinder. Took a while to clean it all out. Sounded like the starter was not as strong as the other. Hard to describe but it just didn’t sound it. Anyway, finally got all the crap out and put new plugs in. Changed the fuel filter, which the element was broken and dislodged inside the housing. Found a couple clamps that were missing from fuel lines off of the accelerator pump and attached those. Then tried turning it over. Got it to fire on a little gas/oil mix I put down the cylinders and the carbs, but would not run. Tried manually pushing the throttle open on the carbs as the girlfriend hit the start button and again would fire but not run.

 

[ZeusDad]

Pulled a starter from another machine that is fairly new(er) and rebuilt. Sounded a little stronger but still wouldn’t run in its own. The starter would engage for a few seconds then shut off on its own. It would go for maybe 5-7 seconds, then shut off. Then maybe 2 seconds then shut off. If I pulled the plugs, it would do the same, but maybe get 10 seconds out of it before shutting off. No rhyme or reason to how long it would attempt to start.
It has a direct ground to the battery. I am getting spark from both plugs and wires. While it was kind of half a$$ running and pushing the throttle open, I got a flame out of the mag carb. I figured the timing must be off. Pulled the carbs and timing cover. Timing (plate) seems okay and the surface it sits against doesn’t seem scored. I’ll order a timing gauge. Anyone think of anything else I might be missing or should look at??

thank you

 

[FlyboyX]

congratulations on your purchase!

Fist thing I would do is a compression check. 150psi is your friend. The goop you pulled out of the cylinder sounds really scary to me. If the boat has been sitting a while. The carbs are probably full of gunk and corrosion. At the very least I would take all the carbs off, clean them well and put new oem mikuni rebuild kits in them. Mikidymic has a rebuild thread that I would suggest reading through very thoroughly.

I might suggest searching my screen name for my very first thread. I was a noob and other users gave me some very good advice that would also very much apply to you.

 

[ZeusDad]

I’m working on getting a good compression tester from a friend of mine. I have a harbor freight one that I’ve since read is prob inaccurate most of the time.
A carb rebuild was on the list. I’ve read through that thread several times now. I’ll order some mikuni rebuild kits and gaskets today.

one thought that crossed my mind was the possibility of the grey mud coming out of pto cylinder and not mag cylinder be an indicator that the top end needs to be rebuilt?? Like if the rings were fried and scored the walls?? Obviously a compression test would show this and/or just taking the head off...

 

[ZeusDad]

Flyboyx... thank you and I’ll search for your earlier threads

 

[ZeusDad]

I set timing on the motor, the degree wheel came in today. Put everything back together and would fire but not run....

checked compression on cylinders, 150 on pto side, 25 on the mag side....

so motor needs a rebuild. I have a 96 gsx with the 787 motor. 150 on both cylinders. This ski was going to be a restore project over this winter for the girlfriend to use, but.... can I use this motor in the speedster?

 

[FlyboyX]

Assuming you have 787’s to begin with, the answer to your question is yes. You may need to use your old boat carburetors and a few other parts. I would save everything. Do a comp Chk on your ski motor before you dig into it

 

[ZeusDad]

Pulled the pump on the port side motor. What’s up with this thru hull fitting??
Looked at the ‘96 gsx I was going to swap the motor in the boat with. It’s a white motor. Does that matter?

Should I just rebuild the motor in the boat and put it back in? I’m hopping it’s just the top end that I need to rebuild.

 

[Theguyinmi]

Pulled the pump on the port side motor. What’s up with this thru hull fitting??
Looked at the ‘96 gsx I was going to swap the motor in the boat with. It’s a white motor. Does that matter?

Should I just rebuild the motor in the boat and put it back in? I’m hopping it’s just the top end that I need to rebuild.

The through hull piece you are seeing is the shaft protector. They are useless and break the second anything enters the pump. I trimmed mine back they say if you leave them on their broke they can cause cavitation. I don't think the motor matters it might be jetted slightly different in the carbs I don't know if the controls are all the same.

 

[ZeusDad]

little update...

pulled the motor apart today. See pics below. This is my first time inside of a seadoo motor.

I’m debating if I should try just rebuilding the top end and take my chances that the bottom end isn’t screwed

or

just buy another motor from Westside or SBT or somewhere else people suggest.

I’m working on somewhat of a budget and trying to do this on the cheap, but be reliable. I don’t want to have to do this again and would like to try to get the boat in the water this summer before the season is over.

....thoughts????

It has WSM pistons. On the mag side cylinder, which is the cylinder with no psi, the rings are clearly shot. No movement and appear to be stuck. The piston is scored and so are the cylinder walls. The pto side had 150psi, but does have some scoring on the inside of the cylinder, the rings are still moveable tho on the piston.

 

[FlyboyX]

the cheapest option is going to be the engine you rebuild yourself. as to your bottom end, who knows? you have the engine in front of you. with that said, i am a huge fan of "doing it right the first time." do you have the service manual? spec it out and see if the components are within limits. anything questionable should probably be replaced. that way you don't have to go through this again next year.