657 Runs good for 10 minutes then

[Lhardy]

All right last time I posted was able to get good answers. I’ve been messaging Matt on here and he’s got good ideas but I’m just running out of options and can’t figure it out.
So I can get it off the trailer and runs great even @ WOT for around 5 to 10 minutes.
Then it starts running out of power to me it’s like it’s bogging/not getting past ideal.


My current set up is a 94 SPX with the 657 .

Of course all fuel lines have been changed.

New fuel filter.

New battery.

New rectifier. (At first I thought this was the problem)

Carburetors just got rebuilt.

Compressions in the high 140s.

Engine is cooling properly.

if you guys need anymore info let Me know

Also I’ve done this for five times now.. if I wait a day it runs good or if I let it cool down it runs good for 10 minutes and then starts acting up again

 

[glsmohio]

Did you try by passing the fuel selector?

 

[Lhardy]

Yea I tried that

 

[glsmohio]

Well it takes compression, spark and fuel so were missing something

 

[Lhardy]

I know, these things are not that complicated...this one making me pull my hair LOL.

 

[Lhardy]

Currently this thing doesn’t run through the fuel selector switch at all, I’ve tried swapping the hoses from reserve and normal still the same.

I even have open the gas cap when this happens to see if I have a venting issue.

 

[Lhardy]

Does anybody think this sounds like a carburetor issue. ??

 

[glsmohio]

When's the last time you checked the filters? Along with cleaning out the fuel tank?

 

[Lhardy]

I haven’t cleaned out the fuel tank, but I have change the filters less than hour of use.

 

[One1]

2 strokes having hot running issues is more times than not compression so what you need to do is test compression then run it until it starts acting up. Pull it back in immediately and test compression asap. There are elements to metal that only materialize when they have reached operating temps at the core. 10 mins to me sounds like a heat soak issue. Once it soaks all the way through and water can no longer affect the entire block temp a compression issue can materialize. If you verify this, only then can you check it off the list. There are only 2 ways to troubleshoot...... Find what's wrong or check off what's right.

 

[Lhardy]

I have an update,

Went out on the lake again today with the same symptoms I did however bring out all my tools that I had...
compression was at 150 for both

I did bring an in-line spark plug tester it stayed Lit on both cylinders.

I did check voltage and I was at 13.5 13.8

I did however notice one thing, I can turn it off and then turn it back on and it runs good for a couple seconds and then goes back to running crappy again.

I also cliper the ends of the spark plug wires a quarter inch back and re-threaded.

I did not see any air bubbles in my fuel lines.

 

[Lhardy]

Help

 

[jhjesse]

Maybe the engine seizes when hot?
While riding does the pee hole have a good flow?
Do you back flush after riding?

At one time I had two 94 SPX skis. One of them would acted very much like what you describe. After doing extensive trouble shooting it ended up having a partially clogged water jacket.

 

[Lhardy]

So I do have water coming out of my telltail. I haven’t tried backflushing it since this happened I can try that, but the engine is cool to touch though I can touch everywhere on it and it feels just warm.

 

[Lhardy]

Thanks for everyone’s helpful advice to date, but were are all the big dogs at, to help a brother out LOL.

 

[mikidymac]

I have seen stators and coils cut spark when they get hot. With electrical parts heat increases the resistance so when they get hot you loose spark then when they cool it comes back. It would test both when cold and hot and see if it stays within spec.

 

[Lhardy]

I can probably Google search this quick, but is there a way to test the stator and coil, what’s the process .

I have a Meter to work with.

 

[MAL]

My 717 is doing the same thing. I have not been able to work on it because the starter went out. Mine does have a water leak, so over heating could be a possibility. How would a person check the temperature on Seadoo?

 

[jhjesse]

Oil pump adjusted correctly?
Have you tried premixing one tank of gas just to rule out oil pump?

 

[MAL]

I have an update,

Went out on the lake again today with the same symptoms I did however bring out all my tools that I had...
compression was at 150 for both

I did bring an in-line spark plug tester it stayed Lit on both cylinders.

I did check voltage and I was at 13.5 13.8

I did however notice one thing, I can turn it off and then turn it back on and it runs good for a couple seconds and then goes back to running crappy again.

I also cliper the ends of the spark plug wires a quarter inch back and re-threaded.

I did not see any air bubbles in my fuel lines.

Does your seadoo die, or just cut out and or bog down?

 

[Lhardy]

Oil pump adjusted correctly?
Have you tried premixing one tank of gas just to rule out oil pump?

So right now the oil pump is already bypassed it is pre-mixed.

 

[Lhardy]

Does your seadoo die, or just cut out and or bog down?

So just Boggs down but it keeps running though...it ideals great still

 

[Lhardy]

OK so last week I bought a carburetor kit even know they were just done recently, who knows if there’s something messed up. Since I have some experience rebuilding carburetors... I’m going to rebuild this one this evening again..I’ll give you guys an update tomorrow on the water.

My symptoms scream fuel or electrical I changed out everything electrical all my lines are clear so carburetor is the only answer.

Like GLS said... Only needs three things to run.

 

[MAL]

So just Bogs down but it keeps running though...it ideals great still

That is exactly what mine is doing. I look forward to your solution

 

[Lhardy]

All right guys it was carburetor carburetor carburetor put a new kit on it... although I didn’t see nothing wrong with the old one something was wrong.

She runs good now

Except for I feel like my throttle is fluttering at full speed I think I need to set the adjustment screws a little bit