The RFI (Rotax Fuel Injection ) Spot

[RDele]

Hi All, I am new to the RFI thread but there sure is some great info in here. I jmnust purchased a 1999 GSX RFI last month that is in great shape and only has 94 hrs on it. Found out the owner was running Amsoil in it so the 1st thing I did was drain and flush the amsoil with BRP full synthetic and replaced the oil filter. Ski is at our cottage on Lake Huron in Canada so because of rough water and time constraints could not get the jetski out for a couple of weeks. Did start it a run it a few times to circulate the new oil around around and it ran great.
So we get it down to the water a couple of days ago and all we get is click- click -click when we try to start it. Grab the battery out of my 1990 SP and boost the GSX. Notice the battery got low enough that the clock on the gauge has gone back to zero. Find out one of the bilge plugs was not tight and the GSX has 1'- 2' of water in the bilge but it doesn't look like it has bothered anything. Put the JetSki on back on the trailer and drain all the water out. Get it started and head out on the water, GSX is running great but only limited info coming up on the info gauge . Only time , rpms are working. run it for 3-5 minutes and then stop to look at something on shore. When I start to head back in the GSX starts bogging out at around 3,000 RPM. Take it in slowly but it starts running a little rougher. Kind of like the choke is on. Shut it down for 5 minutes and have a look to make sure everything from the oil change over is on tight and nothing is out of place. All looks well. Start it up and it is still runiing rough can not really get up to 1600 RPM. It is running like a full choke is on. Shut it down and take it out to charge up the battery. That is where we are at now until I can get it back out on the water tommorow. 2 Questions, Any suggestions as to what may be causing the maschine to run so rough? 2nd Question- when is the last time anyone actually bought the beefed up rectifier from OSD as they are saying they bought there supplier out and are now out of stock. Thanks

Did you bleed the oil lines?

 

[Raymond 88]

Yes, bled the lines a couple of times. Ran really well for a short time after the oil change. Then started stumbling. No error code. 2 beeps when you put the dess key on.

 

[RDele]

Yes, bled the lines a couple of times. Ran really well for a short time after the oil change. Then started stumbling. No error code. 2 beeps when you put the dess key on.

It's a no start situation at the moment? Check all grounds and wires. Sometimes they look good but, you have to tug on the wires at the ground connections. There is one under the motor. There is a ground cluster on the mag cover. Check connection at the starter. Check battery connections. Check inside rear electrical box at relay for snug connections.
Also, use allen wrench to remove the crank position sensor from the mag cover and see if it has metal shavings on it. (They may be small) Metal shavings can give the computer false readings and shut everything down.

 

[Raymond 88]

Anyone else aware of the problems with the GSX 787 RFI fouling the spark plugs very quickly at sustained low speeds? I just heard this is quite common for this engine.

 

[Raymond 88]

Alright almost embarrassingly found the solution today. Pulled the crank sensor and there were metal filings stuck to it and some of them large. Cleaned it up and started checking for loose grounds and wires as already checked all the fuses. Tried to start it, turned over but no start. Pulled out the spark plugs that the last owner installed and only had 3 hours on them. He told me they were "gapped " properly when installed. Checked the gap and it was somewhere around .045 ? Installed new plugs gapped to .020 and it started right up !!! Bad on me for taking someones word on it and not checking it already myself.
Still looking for other RFI owners with a little more insight into the problems with the plugs fouling so quickly.Thanks

 

[Raymond 88]

New Question,
Anyone with any suggestions as to where the red knob on the RAVE valves should be adjusted to on a 1999 GSX RFI 787. I know the manual specs them to be unscrewed until they are even with the valve cover. A Mechanic I spoke with says he sees a lot of them turned all the way in like is recommended for the 951 and he just leaves them that way now if they come in like that.
Thanks

 

[RDele]

New Question,
Anyone with any suggestions as to where the red knob on the RAVE valves should be adjusted to on a 1999 GSX RFI 787. I know the manual specs them to be unscrewed until they are even with the valve cover. A Mechanic I spoke with says he sees a lot of them turned all the way in like is recommended for the 951 and he just leaves them that way now if they come in like that.
Thanks

Even with the top is how I have them. I think that's how the instructions say to do it. There are other variations for top end speed and for out of the hole power. You would have to research those adjustments.

 

[RDele]

Alright almost embarrassingly found the solution today. Pulled the crank sensor and there were metal filings stuck to it and some of them large. Cleaned it up and started checking for loose grounds and wires as already checked all the fuses. Tried to start it, turned over but no start. Pulled out the spark plugs that the last owner installed and only had 3 hours on them. He told me they were "gapped " properly when installed. Checked the gap and it was somewhere around .045 ? Installed new plugs gapped to .020 and it started right up !!! Bad on me for taking someones word on it and not checking it already myself.
Still looking for other RFI owners with a little more insight into the problems with the plugs fouling so quickly.Thanks

Now that you have discovered metal shavings on the crank sensor you might want to remove the mag cover and clean out the inside of the cover, stator, and other surfaces inside. Metal shavings are probably being produced from the starter gear.

 

[griz400]

I would answer your plug fouling issue, but its probably a compression problem, raves should be flush with adjustment, and really i haven't changed my plugs for a couple of years now ...
There is no issue of a plug fouling problem like u state ... that would have made a great commercial in 99 hugh, ride your seadoo at low speeds, stop and replace your plugs, then ride some more ???
This is why i didn't reply for a couple days, and anymore seems i say the wrong things, like i just did ....

 

[Raymond 88]

Thanks RDele, We only have a couple of weeks of the season left up here so I will add pulling the Mag cover to the list of things to do over the winter. Just glad to have it out on the water again, Thanks again.

 

[Raymond 88]

Hey Griz400, Thanks for the constructive feedback. Thought the forum was to help each other out with common issues with there seadoo's , not poke fun at peoples questions!!!!
Funny thing is that the mechanic who told me the 787 RFI had a history of fouling the plugs and to try changing my plugs, actually solved my problem and got the machine running.

 

[RDele]

Thanks RDele, We only have a couple of weeks of the season left up here so I will add pulling the Mag cover to the list of things to do over the winter. Just glad to have it out on the water again, Thanks again.[/QOTE]

Yes, Raymond88, we are winding down around here too. I just got notification from OSD that my rectifier is on its way. I will put it in and do a test run before I have to winterize. Hope this is the fix for me. Good to work with you with the problems on these machines.

 

[Raymond 88]

Thats good news RDele, I think I will grab one of those beefed up rectifiers from OSD as a spare. Take care

 

[LouDoo]

Closing thread.....