717 Rebuild Journey - 1996 GTI

[exoh_e]

Hi everyone, bought two Jetski's early this year and started wrenching a month or so ago. I've worked on a lot of older motorcycle so I have some knowledge of engines etc. So far the 717 and 657 engines aren't that complicated. I was really surprised. I also learn what slipping and cavitation is on my first ride out a few weeks ago. It's funny I've lived on the water my whole life and never really had gotten out on the ocean.

ANYWAYS. I was riding my 96 GTI in the ocean the other day and and boom. I stopped the engine to drink some water and the starter was not turning over anymore. Pretty damn scary. I ended up swimming it to shore. I took the engine out the same day and everything looked good. I was so afraid I exploded a piston or something. BUT I smelled and also heard crunching in the flywheel area. I remember the guy I bought it off said he replaced it? Not sure.

Anyways, bought a new stator(magneto?) and flywheel. Just curious as to a cause of this to happen? Excessive shaft play? Just chance? It doesn't look like the stator melted or anything.

 

[exoh_e]

I installed the new stator and flywheel; I noticed the crankshaft had a lot of vertical play. I split the case and noticed that the two front bearings pretty much fell apart. So it was probably crank play that exploded this.

 

[exoh_e]

I didn't realize the battle it is to get a flywheel coupler off. Placing on new bearings tonight! Anyone have the bearing spacing for the flywheel coupler side(pto)?

 

[mikidymac]

You really shouldn't use that crank, it needs a full rebuild.

 

[exoh_e]

You really shouldn't use that crank, it needs a full rebui

Roger, just got bought a new crank from PWCENGINE; just have to send core back.

 

[exoh_e]

Hm...

So everything's been okay. I put everything back together. I was having some hard to start issues in the water; and eventually it stopped starting in the water. I rebuilt the carbs with an OSDmarines back to OEM kit for the 717. It starts in one-two rotations now in the water. The idle is very strong at around 1400 rpm(It likes staying here). However it became alittle hard to start again. I clipped my spark plug wire ends and that issue went away. The ski between 0-5% throttle is fine?, than 5-70% it's very boggy(Still will climb through the range "okay" feels better when you just start the engine), I heard a pop from the carb a couple times when I got on it(hard accelerate) (Backfire? never heard that before until today ); than at 80-100% it takes off and runs around 6200-6700 rpm very strong(according to my aftermarket rpm meter) clocked top speed at 46 mph. The mag side feels pretty damn hot compared to the pto side. I tried to turn up the low side screw 1/4 a turn and it felt sputter-y when I gave it acceleration; but still got to WOT after the bog.

LOW- 1-1/4 ( 2.25 turns) HIGH- 0


Also. Battery is strong and good, New pump, New Crank, Rectifier, Wear-ring, I made the carbon seal pretty snug and tight, I have the fuel line running off the res right now to delete the water separator just for testing. Compression numbers were fine. The rotary valve seems smooth on both sides. No gouges.

On my 94 spx, its EXTREMELY punchy and has a solid pull through the entire thing. On that ski the mag side feels hot, but equally as hot as the pto side. But from 0-100% its on it. My gti is kind of suppose to have some punch right?

 

[etemplet]

Shouldn't be backfiring or bogging. It might be lean on one cylinder thus a carb issue. Check the spark plugs they might tell you what's going on. Good Luck!!

 

[exoh_e]

Even burn, nice light brown on a plug chop.

 

[etemplet]

Perhaps your rotary valve gear is "not" spot in with regard to the timing.