Starter Engages When Battery is Connected 97 GTX

[GGuillot]

Haven't gotten any responses on my other thread. I may have overextended myself. I started thinking about the ignition timing. I was over complicating this. Regardless of the EIN #, the GTX 787 has fixed timing. The Rotary Valve is fixed at 147°. The Arieltek MPEM allows for timing correction. So naturally I started thinking that if I want this to run as it was I will need to set this at 0° correction. I could advance it up to 3° if I wanted to and maybe make a little more power on top. I don't want to risk detonation so I will try EIN #1 for 0° correction and see how that goes...

Went out there today and opened up the grey box. Re-programmed the timing correction to 0°, EIN #1. I'm about 90% sure my lack of power on top was a result of having my timing correction delayed -3°. Ski started right up and seemed to have all the marbles but as we know everything runs great on the trailer lol. Made sure the rev limit was set at 7200rpm. Not sure that I want to increase the rev limit on a stock motor. Wish someone might be able to confirm if that is safe or not. I can program it to 8k, 9k or 10k. I figure those corrections are only for different intake, exhaust or prop.

Thank goodness that only takes a few minutes to do. Setting back to back records today in Phoenix. 113 yesterday (record) and today, 114 (record). No worries, IT'S A DRY HEAT! haha!

As far as timing in the MPEM, you may be guessing with setting it. Marking the pto flywheel at TDC (mag) and putting a mark on the bracket will give you a baseline. Start it, then with the timing gun, (strobe light) induction off the mag cylinder spark plug wire you can verify where the timing is. I did this last year on my 97' GTX after installing my newly built engine with the SBT crank I got.

 

[Ckrawiec]

That number has always fascinated me....7000 rpms = 166.6 revolutions per SECOND....that is just stupid fast....no wonder when things go mechanically wrong...they go really wrong....haha! and to think we are 'SITTING" on top of that.....Crikey. That is a sobering thought!

 

[MexicoJoe]

**Update**

Had a few hours today to go test the ski. Got to the lake with the MPEM re-programmed for EIN# 1, 0° of ignition correction. The ski did pick up 4mph on the GPS from previous ride. However, ski was still hitting rev limiter at 6100rpm. Got back to the trailer and re-programmed again. This time I only advanced it one more degree, EIN #4, 1° of advanced timing. While the box was open I decided to re-program the rev limit and went up to 8k.

Went back out and BOOM! Rocket ship! Just like before! Ski was hitting 6780-6820rpm all day at WOT and the power curve felt really good. I'm not sure that raising the rev limit did anything because I made both adjustments at once but I can definitely tell that the EIN #4 for 1° of advance is where it needs to be. The engine ran great as it has the two years I've owned it and top speed was ranging between 49.8 and 50.2 with the high for the day at 51.5mph!!! That is GPS speed from the Garmin sonar/GPS.

Overall, I was extremely pleased and very relieved that the corrections made a difference and the ski is back to running like a top again. Very pleased so far with the Arieltek MPEM for $290 + the $3 I paid for 2 year full replacement protection... Hopefully I won't have any issues in the near future.

CHEERS!

Joe

 

[Ckrawiec]

**Update**

Had a few hours today to go test the ski. Got to the lake with the MPEM re-programmed for EIN# 1, 0° of ignition correction. The ski did pick up 4mph on the GPS from previous ride. However, ski was still hitting rev limiter at 6100rpm. Got back to the trailer and re-programmed again. This time I only advanced it one more degree, EIN #4, 1° of advanced timing. While the box was open I decided to re-program the rev limit and went up to 8k.

Went back out and BOOM! Rocket ship! Just like before! Ski was hitting 6780-6820rpm all day at WOT and the power curve felt really good. I'm not sure that raising the rev limit did anything because I made both adjustments at once but I can definitely tell that the EIN #4 for 1° of advance is where it needs to be. The engine ran great as it has the two years I've owned it and top speed was ranging between 49.8 and 50.2 with the high for the day at 51.5mph!!! That is GPS speed from the Garmin sonar/GPS.

Overall, I was extremely pleased and very relieved that the corrections made a difference and the ski is back to running like a top again. Very pleased so far with the Arieltek MPEM for $290 + the $3 I paid for 2 year full replacement protection... Hopefully I won't have any issues in the near future.

CHEERS!

Joe

Great news....excellent info. Thanks for sharing your process and information...every little bit helps.

" I feel the NEED for SPEED".....

 

[Roy N]

That's what I've been thinking too. Is there any chance it could be the switch (start/stop button)? If there is a short, what wire would likely be the culprit? I know the mpem gets its power from one of the red wires in the rear box. That's the fused red wire that's plugged into the rear box correct?

One other note, my battery was good at 13.2v during our trip and for the last year. What could have changed in the 3.5 hour drive home? How could something short if everything was previously good? I have owned the ski 2 years and have never had any electrical issues whatsoever.

I considered the fact that something shorted and ran the starter while the ski was parked without my knowledge and killed the battery... I always store my battery inside my home when the ski is not in use to prolong the battery life but after getting home late and knowing that needed to flush the ski the next day I left it hooked up overnight. I've read that salt water in the rear electrical box can create continuity on the solenoid and jump start the starter... any chance that thing ran for a period of time and melted something?

Jeremy thanks again for the quick response.

 

[Roy N]

I had the same issue on my Arieltek MPEM I put in my 96XP. Worked normally for 5 hrs. or so then whenever + battery lead is attached the starter turns uncommanded constantly (no starter button push). I thought about it & decided to get in my used Seadoo electrical parts box & splice in a new starter switch button like on my 94 SPX in the wire from MPEM to starter solenoid. This was 2 yrs. ago & still runs good for stock engine / pipe making 6950 RPM on a good day. New start sequence is DESS key on, Push original red start button on left bar & hit new starter button next to DESS post. Sort of funky way to do it but it starts nicely & runs normally otherwise.