2001 GTX RFI "limp mode" limited to 4400 rpm

[Jpnovak]

The RPM is pinned and not making power.

The rpm is low enough that it will get about halfway on plane with me (200#).

I also wonder if the coil fails into single channel. Not sure what rpm a single cylinder could support.

 

[etemplet]

So are you backing off the throttle to find the sweet spot for the RPM.? Example would be how little throttle you can give the ski and have the same results. That is where I would feather the throttle to see if I could get a few more RPM. when I'd get mine to 4300 she'd take off and run strong to 6900. It wasn't the raves but it sounded like it was hitting a rev limiter.

 

[Jpnovak]

The ski will not accelerate or pull despite any amount of throttle. If you slow down back to idle or just above the cycle will continue. sluggish until you hit the same RPM. No codes, no beeps, no "Maint". Just limited RPM.

When cold, there is smooth power delivery through the planing process to max rpm. Runs right up to 6800 limit.

 

[mikidymac]

Running fine when cold then having issues when hot was the stator going bad back in the day on carbed skis. Could be on the RFI also. As the stator heats up the internal resistance increases enough to cause issues.

 

[Jpnovak]

Thanks. Stator measures out fine. I pulled the cover and no shavings. Same with crank sensor.

The voltage is charging normally within spec and this problem occurs with /without the rectifier plugged in.

I just can't figure out why the ECU is telling the engine to go into limp mode.

I still need to check the voltage at the MPEM. I have not had a chance to install some jumper wires inside the connector.

 

[mikidymac]

As a last resort, the stators can test good and be bad when hot. THe old Kawasaki 440/550's were notorious for this.

 

[etemplet]

The ski will not accelerate or pull despite any amount of throttle. If you slow down back to idle or just above the cycle will continue. sluggish until you hit the same RPM. No codes, no beeps, no "Maint". Just limited RPM.

When cold, there is smooth power delivery through the planing process to max rpm. Runs right up to 6800 limit.

Yep the RFI's can be tricky. I have what I've heard called a megger and have thought about using it to check the system but I'm not sure it is 100% safe. You connect the wires and crank the handle and the meter will read the voltage breakdown. Sometimes I think the wiring harnesses may be suspect on these skis or the plugs. I had a ski one time that wouldn't carry the amperage needed but read 12 volts on the volt meter. Wire ended up being corroded internally under the insulation. It gets tricky. Good Luck. I'd find a swap out MPEM and give that a try. I'll be following this thread.... we'll all learn something.