98 GTX-RFI Problems

[Drweird13]

First off its not my PWC, but I'm stuck fixing it, so the history of the boat is limited. It has 33 hours on it, and just got done sitting for 2 years. I cranked it up in the driveway before we took it to the water to see if it would run. I fired it up, and within 5 seconds turned the water hose on connected to the quick connector. It fired right up, idled fine. Did the pre-operation check per the book. So I took it to a lake close by to see if it would run before we hauled it on our trip. Ran fine at the lake (30 Minutes, 2 people, 40mph). Hauled it to the beach. Put it in the water, took it out and towed a tube for about a hour no problems. Then it started having problems. As I was towing the tube, it started loosing power, I let off the throttle, and the engine died. Waited about 10 seconds tried to crank it again. The starter wouldn't turn the engine over the first try. The second try it turned it over but wouldn't fire. After about 4 seconds of turning the engine over, it fired, idled fine. We started to head back to shore. Engine lost power and cut off again (About 30 seconds after starting). Decided to tow it back. Towed it back to the dock, and cranked it up to see if we could spot a problem. It idled fine, had a water stream and wasn't overheating. Oil was in the exhaust output (You can see some small amounts of oil in the water). We decided to idle it around to see if it would cut off again, it didn't so we took it back out to the open water and it ran fine (About 10 minutes, brung it back in). Next day we took it back out to tow the tube some more. Towed the tube for about another hour, no problems. Then it did it again, lost power engine cut off. I think we were able to idle it back to the dock this time. Took it back out to open water same day, but this time only took about a minute before it cut off. Parked it for the remainder of our vacation.

Also, when running it at 4500RPM, I can notice that the engine is missing: the engine randomly not firing for a short amount of time. Above 4500RPM, I cannot notice this symptom.

When idling, it will sometimes idle 1700RPM and sometimes 2200RPM or anywhere in between.

The speedometer on the craft says top speed of 43MPH, (two people riding).

This is my first time riding a PWC. Throttle wide open, it would run around 40MPH and 7000RPMs.

After idling in the driveway, the spark plugs look a little rich.

Air filter is free and nothing clogging it.

Propulsion system looks fine, nothing clogging it.

Any Ideas?

Thanks.
-Brian

 

[lakedog1]

Spark plugs and rectifier

Check the volatge at the battery before starting and after. The voltage after should be about 14, an increase. If the voltage does not increase when its running change the rectifier on top of the rear electrical box, a 2 minute job. I know when I pull something behind my ski my spark plugs load up very quickly and my ski runs horrible the next time I try running it. Try cleaning or replacing the plugs. Also check the small black vacum lines running to the powervalves for a problem. A loose or disconnected line will limit your RPM when on the water.

 

[Drweird13]

Put new plugs in it. Voltage indicates charging (~13.5v). Took it out in the water. Nothing changed. Still missing at mid RPM's, about one miss every second. Rode 30 mins, cut off, wouldn't fire had to be towed back. Wouldn't fire at the dock, starter turns motor over fine, and can smell gas fumes, so I'd say its pumping gas. Fired up and ran in driveway when I got home. Spark plugs show signs of being really rich (black), both cylinders the same. Sounds like the coil(s) right?

The plugs that were in it were gaped too much, around .038 in. I gaped the new plugs to .022 per the book.