1996 GTX Fouling rear plug

[Lamrith]

I mentioned I would make this post in my welcome thread.

Dad has 1996 GTX, had a long and well used life, purchased new in 96, no exact hours known, but probably a couple hundred.

Last year the throttle cable was very stiff. We traced the cable and found the Oil pump Assy was "gumed" up and not rotating freely. We were able to work it by hand and clean it up and get it rotating again. Nobody local had one available. Ski ran great rest of last year.

This year pulled her out, ran thru her and put ski in water, she fired right up. Took it out close to dock to warm it up and clear it out. Ran great for a couple passes full rpm no problem. Then started bogging down, would not maintain rpm, got to the point had to idle only and just got back to dock. Rear plug was fouled. Swapped plugs on dock, connected hose and fired up, would rev a few times hen started bogging again and not even idle. Same rear plug was fouled and smelled a bit oily.

I immediately suspected that oil pump assy since it was bad last year, but that should foul both cyl? Based on recommendations here in other threads I ran compression. Front 135, rear 120.

I just looked again, still grey fuel lines:facepalm:. I know this ski has never had work done to it before, it has just been that solid. I will give the list of items to my dad so he can get the hoses and primary fuel filter replaced.
I have to look into the carbs/filters/selector though. He does not have the tooling to tackle that job which means hiring someone and I do not think he wants to put a bunch of $ into a skit that is not worth much.
I am also concerned about the 15psi spread in compression, thoughts?

Bad part is I leave today and not back until next year to work on it.

You may want to post specific questions in the 2 stroke PWC section from the home page.

But I will point you in the right direction of common poor running issues

1. Check compression is vital! Should be at 150 to know motor is healthy. 90-120 may/will be giving you trouble.
2. If you have grey fuel lines they MUST be change out to prevent good motor going bad mid season.
Also clean/replace fuel selector.
3. If your changing the fuel lines then the carburetor HAS to come off and gone through entirely.
They have small internal filters that may be clogged
4. Clean/Inspect the RAVE valves.
5. If all of above checks out and its still not running/caviating then look at the pump.

Hope that helps....

 

[AdamXP800]

That compression is low, low enough it probably won't run right. Verify those numbers again or with a different gauge

 

[Lamrith]

Yeah I am worried about the low # as well. I ran compression 3x each cylinder to verify. rock solid same each time. This is a high hour ski, 200+hrs, never been worked on, so I unfortunately would think it is ready for some attention? The difficult thing is that the motor runs awesome until it fouls. Lot of power, pops right out of the hole onto plane..

I do not have access to a second compression tester at this time. I will see if dad can test it with another one after I leave. Maybe it is 150f/135r and not 135f/120r if the gauge is off? What is too big a spread that will cause problems?

Talking to him, he is not interested in putting much $ into it as they only use it the 2 weeks we are here, as they have a newer ski in the boat.. Pretty much sits otherwise..