1995 Seadoo GTS Engine starts (sometimes)

[sunslinger3]

Hey all!
I have a 1995 SeaDoo GTS, and after I took it out of storage this winter, I started it up just fine at first. But After I transported it up to the lake, I put it in the water and all it would do is turn over. The electric motor would run and the jet would slowly push water but no combustion occurred. After 20 mins of that it started to sputter and eventually I was able to get it started by feathering the accelerator to keep it running. The next day I took it out, it would only turn over until the battery was very low and then it sputtered again until the battery completely died. I charged the battery but it still isn’t doing anything more than turning over. It’s full of good gas, and im going to replace the plugs just because it’s a cheap quick fix. The engine seems to run perfectly fine when it does actually start, and I put carb cleaner in just incase the carb was clogged. If anyone has any suggestions Im open to them!
Thank you!

 

[mikidymac]

Carb cleaner will do nothing but possible remove the oil film from the engine. This is a 2-stroke and carb cleaner will not help anything.

First check for spark and second see if a little premix down the carb will get it to fire. If it does then you need a full fuel system and carb rebuild.

No "Fix-in-a-can" will help these.

 

[sunslinger3]

I added the seafoam only because it tried to start after I added it and the gas in it was a year old. Spark is there, but weak so I bought replacement plugs. Compression is 97 and 98 psi. When I put starter in it, it will fire and the engine starts and tries to run after that so I’m guessing it’s most likely something electrical. But I’ve also seen something about a damaged rotary valve that can also cause the same thing.

 

[KyleW2]

I added the seafoam only because it tried to start after I added it and the gas in it was a year old. Spark is there, but weak so I bought replacement plugs. Compression is 97 and 98 psi. When I put starter in it, it will fire and the engine starts and tries to run after that so I’m guessing it’s most likely something electrical. But I’ve also seen something about a damaged rotary valve that can also cause the same thing.

97 and 98 PSI? Test it with another gauge. If it’s truly that low it’s rebuild time.

 

[mikidymac]

As Kyle said, if it is really 98 psi then it will not run especially in the water.

 

[sunslinger3]

97 and 98 PSI? Test it with another gauge. If it’s truly that low it’s rebuild time.

Thanks Kyle you saved me on that one, another gauge reads 146 and 148 I’m so used to rebuilding small outboards so 98 seemed normal to me.

 

[sunslinger3]

Thanks Kyle you saved me on that one, another gauge reads 146 and 148 I’m so used to rebuilding small outboards so 98 seemed normal to me.

Today I have time to run through at least the important tests on the troubleshooting checklist, so I will update and add information if I’m unable to come to a consensus or if I fix it.

 

[KyleW2]

Thanks Kyle you saved me on that one, another gauge reads 146 and 148 I’m so used to rebuilding small outboards so 98 seemed normal to me.

Good deal. I was surprised that the two cylinders would be nearly identical in psi being that low which is what made me question the gauge.

 

[sunslinger3]

Okay so after taking the plugs out, it narrows things down a little bit. There was oil covering the plugs so I just cleaned them off, it could be a piston ring or carb issue, but since compression is good, do you guys think that it rules out the rings?

 

[mikidymac]

Excessive oil on the plugs has nothing to do with the rings on these. It could also cause false high compression readings so retest compression once the oil is burned out.
Typically it’s from bad inner crank seals or rotary seal.
You need to crank it with plugs out and clear as much oil out then get it running to burn out the rest then see how fast it comes back.

 

[sunslinger3]

Okay I will try that next, I did take the spark plugs out again, cleaned them and then put one in and held the other near the engine. It tried to start but no spark on either of them. I would also like to note that a little bit of smoke comes out of the cylinder when one plug was out.

 

[mikidymac]

Without spark it’s not going to start. Sounds like you have more going on here.

 

[sunslinger3]

I don’t know what I did, but it just started first try with 0 hesitation and idled mostly fine, but there’s oil leaking out of the plugs, I think I hand tightened them though so let me see what happens when I connect the house and tighten them down all the way.

 

[mikidymac]

You really don’t need the hose. You can run it a minute or two and be fine. Really no reason to run it longer than that anyway.

Just put your hand on the engine and when it feels too hot turn it off. Also rev it up a few times to blow out any excess oil.

 

[sunslinger3]

Okay so, I wasn’t able to flush the oil out, but I did run it a few times in water and took it for a test ride while running (I was hoping to find some irregularities with it running) and here’s what I found:
It ran in my driveway (no hose for 2 minutes) before dying, I brought it to the water and it wouldn’t start again until I took the plugs out and put them back in. Then it started up first try, and I ran it out into the bay (it ran very rough at idle) but it was perfect at full speed until the engine just completely stopped, I figured it overheated since it stopped so fast and didn’t sputter like if it was too rich for the engine, so I paddled back until it started again. I rinsed and repeated that run, trying to mess with as many variables as possible. It follows no pattern but it will not stay running at low speed or high speed. I tried to get the oil to burn out but I think it was burning oil the entire time because of the amount of smoke and the smell. I tried cranking it with the plugs out to drain the oil and the oil came back after about 5x 7 second cranks. The plugs sparked after I cleaned them off both times, which is probably a result of the oil system. I have never worked on an engine that’s oil injected so I apologize if I’m not very knowledgeable.

 

[mikidymac]

IF you are getting that much oil, that fast sounds like your crank or rotary seals are shot. You could try disconnecting the oil pump and premix but that is a long shot.

 

[sunslinger3]

I have a feeling it’s the rotary valves based on my research online which is fine, I’m cool with replacing that. If I can find the oil pump I’ll go ahead and disconnect it and use some premix when I’m up at the lake. What should I use 50/1?

 

[mikidymac]

I like 40:1.

 

[sunslinger3]

Okay, I’ve been at the lake today, I used a brand new compression gauge and the readings I had at first were closer, both cylinders are about 85 and neither seem to be getting spark with the inline spark tester. Sounds like it’s rebuild time but that’s gonna suck. Maybe more than one thing seems to be the problem here.

 

[POPPS]

Seems like compression gauge is wayoff.