96 XP intermittent loss of power

[Gary Arreaga]

96 XP intermittent loss of power

Symptom:

Running on plane it suddenly losses power, does not die, butwill only idle. Feels like it’s running on one cylinder. If I throttle it up itwill just bog down, but again will not die. If I shut it down for about 30sec and start it back up it will runstrong for the rest of the run or for about 3sec and bog down again. Chokingthe engine, to see if it was lean, only stalled it.

What I have done:

Took the carbs off, inspected diaphragms needles, seats,filters, pump and all relevant internal parts. I did not come across anythingthat looked faulty. Adjusted the needles to be flush with carb body assuggested in the manual. Checked thepop-off valve, I know it holds past 30psi, but not sure of the actual pop offsince my gauge only goes up to 30psi. The one test I could not conclusively geta result was the feed and return check. Whereone way you can suck air through and not push any the other way and vice versawith the outlet. I had resistance in this test but not a solid in-pass.

Once carbs were fitted I set needles to the recommended oneturn out, however after running the ski and pulling the plugs; I found themwet. I ended leaning the carbs about a quarter turn in order to get a nice dryplug. Not too much though

Thanks
Gary

[Technical Support]

Re: 96 XP intermittent loss of power

23-43 is correct pop-off so I dont think thats the issue, what is the engines compression?

[Gary Arreaga]

Re: 96 XP intermittent loss of power

Compression is a whopping 175psi on both cylinders.

[Technical Support]

Re: 96 XP intermittent loss of power

Try running a fuel line directly from the tank to the carbs.

[Gary Arreaga]

Re: 96 XP intermittent loss of power

I did not run a fuel line directly from the tank. I got side tracked with a partially restricted fuel shut off valve.

I found the fuel valve about 2/3 restricted. I ordered one from SBT, shame they don't make a repair kit, it was on back order for a couple of weeks. Upon arrival I fitted the new valve along with all new fuel hoses, ski still had the old grey hoses. I did not find any collapsed hoses, however.

I was sure the restricted valve was the source of my problems, But it wasn't!!!

Here is what I got now. Ski starts and dies, if I pump the choke it stays running. After about 15 sec of that I can throttle it up, bogs about 1/2 throttle and then clears and runs good. If I bring it down to an idle and let it run about 30sec it stalls again. sometimes it restarts and other times I have to pump the choke again. I can't help but think that it's starving for fuel.

Is it possible for the fuel pick tube/baffle assembly to be the problem? Cracked, plugged? I will run a hose directly from the tank in the next couple of days, in the mean time if yo have and other suggestions I would be grateful. By the way, I took the rave valves out and cleaned them. the stator cylinder has scouring, lack of oil? lean mixture? not sure, but compression was 175psi on both holes.

[Gary Arreaga]

Re: 96 XP intermittent loss of power

Update:

I ran a hose directly from the fuel tank, no change.

I ran the ski out of the water, with a connected hose, it had the same bogging symptom, however, it does not stall. It idles without a problem as well. The load makes it brake down; could this be an electrical problem instead of fuel related?

I did find a broken spring in th water regulator, but I don't think that is the issue.

[Technical Support]

Re: 96 XP intermittent loss of power

Still sounds fuel related or carbs not set up correctly, maybe go back through them.

[Gary Arreaga]

Re: 96 XP intermittent loss of power

I went back and removed the carbs once again. This time I acquired a high pressure pump in order to check the pop-off pressure. The PTO carb released at about 43PSI the mag carb released at about 48PSI, this is an average after 6 or more tests.
I'm not really clear how the adjustments are made, replacing springs or needle valve adjustments.
The needle valve lever (has a silver spring) is set flush with the check valve assembly housing.Does it need to be set flush with actual carb body instead of check valve?

[Technical Support]

Re: 96 XP intermittent loss of power

It needs to be set across the inside of the carb body, not the upper surface where the cover mounts.

[Gary Arreaga]

Re: 96 XP intermittent loss of power

I understand it needs to be set across the inside of carb body, but is the needle valve adjustment housing ( half moon piece that is screwed in) considered part of the inside of the carb. It stands proud of the actual inside of the carb by maybe 15 thousands. Secondly if it's off, do I change springs to adjust pop-off pressure?

Thanks for you time and patience!

[Technical Support]

Re: 96 XP intermittent loss of power

don't measure off the 1/2 moon part, yes to changing the spring to adjust the pop-off