GTX RFI ..... won't stay running

[konlao77]

my ski won't stay running after bout 15- 20 min. I take it out and start up fine and runs good for bout 15- 20 min. then all of a sudden stalls and dies and will not crank back up until it seems like it cools off but not really sure. recently I noticed on one of the RAVE valves oil is leaking out of it. I opened it up and found the upper spring clamp has came loose and oil was coming out from under bello...... removed the other just to inspect and found that it also had problems, Lower spring clamp on bello had rust and broke in half...... opened this up and found grease in bello and the other had oil. the one that looked cleaner had grease in bello and the plastic cap sat lower ....... IS THIS THE PROBLEM , IF SO HOW DO I REPAIT IT AND PREVENT IF FROM HAPPENING AGAIN.........

[dank]

Re: GTX RFI ..... won't stay running

Not the running problem just a sign of no periodic maintanance. It is common for them to fail after some time. I would rebuild them every two years to keep them clean and in good condition. You should remove the valve from the cylinder and clean the carbon deposit from the valve and the valve guide area.

The running problem sounds like a stator going bad when it gets heat soaked.

[Denny Moran]

Re: GTX RFI ..... won't stay running

Do you have to charge the batt regularly?

[konlao77]

Re: GTX RFI ..... won't stay running

no, why...... I take the ski out pretty regularly when it runs o.k, this problem just occured sat.

[rlr267]

Re: GTX RFI ..... won't stay running

I have a '99 GSX-RFI with the same problem. It starts strong, runs for a few minutes and then stalls out, except, I can give it a little throttle when engaging the starter and it will start again, although it is very week and will not go above 1750 RPM.

Just a little background, I bought this ski in January, I was told it was good and ran strong. However, based on the date on the title (I bought it from a dealer that sells only used boats) and the registration sticker, I have reason to believe it has not been in the water since 2003. I put a fresh battery on it, removed the plugs and put 2 teaspoons of 2cyl. oil in each cylinder before trying to start. The motor turned very slowly at first, at best 4 RPM. I waited 10 minutes hoping the slight movement would lubricate the cylinders, which it had, because when I tried the second time, the motor turned over smoothly. I ran the starter with plugs out for about 15-20 seconds, waited a minute and repeated. Then I installed the plugs and it started on the first try. I let the motor run for 10-15 seconds and pulled the lanyard, checked the drain plugs, etc. and took off for the lake. When I got to the lake, it started right up, and the jet drive appeared to be working fine. I left the ramp at slightly over idle speed out to the No Wake markers (about 1/4 mile) and slowly opened the throttle, as I did, the boat acted as if it were about to jump off the starting line like a race horse then suddenly bogged down.

I immediately let off the gas and it stalled. I cranked without touching the throttle, and it would not start. So I added a little throttle, it started right up but would not exceed 1750 RPM. I eased it back to the dock, got it on the trailer and headed home dissappointed. When I got home, I installed the lanyard to blow the water out the pipes and it started no problem. It even ran up to 5500 RPM. I did not want to pull the throttle any further than that running dry, even if it was only for 10-12 seconds.

For the record, I think it blew far too much smoke, all of it white, which indicates to me it is running too rich, but this is a fuel injected motor. First, does 2cyl. oil burn white? Is it possible my oil injection pump is stopped up and causing the motor to tighten down? Can the injectors be checked by an individual with some mechanical apptitude of do I need a shop?

I read several other links about overheating and some tube from the exhaust that could be clogged, but I am new to this ski, so I do not know the terminology, what tube do I need to check and can someone tell me where it is physically located so I check the right one?

Finally, since I know this question is going to come up, it could be gas. The ski had half a tank, I did not think to drain it and just topped it off with fresh gas. I don't know if the prior owner or dealer put Stabil in the tank. I am more than willing to sacrafice $10 worth of gas to find out if that is the problem. Is there a simple way to drain the tanks on thes boats? I know the GSX-RFI does not have a fuel bowl, is there a filter somewhere?

What else should I check? I have at least 30 shops in the area to work with, I just don't want to miss the Labor Day Weekend waiting for the shop to make a simple diagnosis. Anything I can do to rule out the easy fixes would sure help me feel better and may even salvage the long weekend.

[frankey01]

Re: GTX RFI ..... won't stay running

I would say check the carb low and high speed screws first and you knowing or having a feeling that it had sat since 2003 and you didnt change the fuel? I would definitely pump out the fuel and replace then rebuild the carbs unless you can verify from the dealer that they were already a short time ago.

[John Kubiak]

Re: GTX RFI ..... won't stay running

frankey01, Umm, the last time I checked, the Rotax Fuel Injection systems did not have any high or low screws to adjust...Not to mention that there are no carburetors either.

[1fastski.com]

Re: GTX RFI ..... won't stay running

white smoke it fogging oil burning off , let it run on a hose for a few min put in new spark plugs then go to the lake and give it a try . this is for the sec post i didnt read the first { going to now }

[frankey01]

Re: GTX RFI ..... won't stay running

I didnt even see the RFI in the topic line sorry

[Denny Moran]

Re: GTX RFI ..... won't stay running

After eliminating the blatantly obvious, I would start with new plugs, re-zeroing the tps and resetting idle on both skis mentioned above. (need programmer) possible aps faulty as well.

if no work, look further.

Sorry I can't be of more help but need the ski's in front of me. (bit hard when Im in Australia)

[rlr267]

Re: GTX RFI ..... won't stay running

I cleaned the RAVE valves and the boat runs much better now. I started it up to discover it was misfiring pretty sever on the number two cylinder (aft). When I pulled the plug wire on the number one cylinder (front), the boat would run extremely rough, but with a little throttle could remain running. When I pulled the wire from the number 2 cylinder there was no noticable change at idle. I replaced both plugs and that made a huge difference, the boat now runs good, but continues to misfire at high RPM (5500 and above). I am also receiving an error message on the console reading "12 volt low".

I still have managed to siphon out 90% of the fuel. Anyone know a better way to get the remaining fuel, or could I add a little STABIL to the tank and top off?

The battery is on a charger. Any other items I should check while I am in the engine compartment before I go to the lake?

[tom21]

Re: GTX RFI ..... won't stay running

I would suggest to check the compression with a quality gauge first. and I just had a similar scare concerning running a fuel injected ski out of water. After a rebuild I was running on hose and I guess without the back pressure provided by the water it would not run very well except maybe at idle . different story once in the water.

the reason I would start with compression is if 1 cyl is a little weak I believe you will go into limp mode. anyone else confirm?

[Bill O'Neal2]

Re: GTX RFI ..... won't stay running

12 V low on the message center means either the battery is low or bad, or the rectifier needs replacing ( if the charging system is otherwise good).

When a rectifier goes bad, it creates electronic noise that screws with the ignition, and can make a ski run badly with misfires.

[rlr267]

Re: GTX RFI ..... won't stay running

Compression is 150 on both cylinders. I put fresh gas in and took it to the lake this weekend, it would barely idle at first, however, after a short warm up at the dock, I took it out and it ran great. The water was rough, but I did manage to get a good run (6890 at 53MPH). The information center registered top speed of 59 when I checked. All this assumes the guages are correct. It idled fine after the first run and started great the rest of the day. I think the "bad gas" that was still in the lines had to run through.

I am still getting a continuous Volt Low warning, despite charging the battery before leaving the house. I am going to find links on this forum with information on checking the voltage regulator and rectifier. Anything else that may cause this problem? The battery is brand new. In fact, I put new batteries on both skis (the other is a Yamaha) and tried switching them, still have the same problem with either battery, but no problems with the Yamaha with either battery.

[Bill O'Neal2]

Re: GTX RFI ..... won't stay running

Put a voltmeter on the battery, note the voltage. Now, start the motor and check it again. At 4000 rpm it should read at least 1V higher at the battery. If not, it is not charging and probably needs a new rectifier. ( very common problem).