View Full Version : Motor cutting to idle when in swells

09-23-2013, 04:58 PM
I have something a bit strange going on. When in swells, 2ft., and going just over 30 MPH the motor is going to idle after a couple of good hits.
I have the throttle at speed and the engine goes to idle without touching the throttle.
As soon as I put the throttle back to neutral I am able to bring it back into gear and start moving.
It doesn't get rough or cut completely. Seems like it is going into a limp home mode of some kind.
It has a fresh oil change and the v-drive is full. Any ideas?

Have a 2007 XLV Gravity Games with an Indmar 325.

09-23-2013, 05:18 PM
I'd start with the connections to the computer

Ian Brantford
09-23-2013, 05:59 PM
Check engine temperature. Going much above 180 degrees will trip limp mode. This happened to me this year due to a clogged cooling water intake.

I would also re-seat (unplug and plug in) every connection that you can reach under the dashboard. Some could have shaken loose. Many connections on my boat came loose during delivery from dealer to my local marina (500km drive on rural roads) and had to be re-seated after causing niggling issues.

09-24-2013, 09:34 AM
Water temp was good, just under 180. I keep a pretty good eye on that.
I am thinking electrical also. I was replacing my ballast system last night and started playing with wires but nothing seemed bad. Pulling connections may work.
It is consistently only when hitting waves so it seems to be related to something loose.

09-26-2013, 11:10 PM
It could be your seat bumping against the kill switch. I just went through this. I found that the right side of the drivers seat is less than an inch from the switch and it would just get slightly bumped and the rpm would die but not turn off.

09-27-2013, 01:22 PM
Thanks for that. I had been following your thread on this also. I didn't realize your's wasn't cutting completely. I think mine might be different because my throttle is forward, no rough conditions due to slowing but it stays at neutral. I would think with a kill switch it would die and come back on once the switch was left alone.
Mine idles until I bring it back to neutral then I can bring it up to speed.

Maybe when the kill switch is activated it goes into a limp mode until back to neutral? I will check that out this weekend. If that is is problem solved.

It sounds like the RPM gauge has a loop back to the computer. If it is too high it cuts. Mine tach is at 6k (pegged) when at half throttle so my gauge is bad. I will look into that.

In the mean time I purchased a Yamaha kill switch and lanyard. I have those on my Yamaha wave runners. I have a Blaster and a Super Jet that I ride in the waves and jump and they NEVER cut unless the lanyard is yanked out. This is one for inboard but has the same mechanism as the skis it looks like. Your thread inspired me to do it. I will let you know how it goes. These stock switches are WAY too touchy.

09-28-2013, 12:42 AM
I think your baby is trying to tell you, nicely, that she don't like wave jumping at wide open throttle!!

09-30-2013, 09:37 AM
I think your baby is trying to tell you, nicely, that she don't like wave jumping at wide open throttle!!

Ha, maybe! Wasn't going any more than half throttle though.

So I was out all weekend and it didn't cut out once. the difference was that I looped the kill switch lanyard over the throttle. On the second day while cruising I pushed in the switch just barely and it went to idle just as it did before. I learned that the kill switch can put it into limp mode.
Looks like that solved the problem but still waiting for it to happen again. Will be working on a mod for this thing to make it more robust.

09-30-2013, 02:41 PM
glad it worked. That sounded exactly what was happening with mine. It would drop to idle when I hit a big wave or turned hard to the left which would push the drivers seat over to the right just enough to squish my hat up against the kill switch. Those switches are way too touchy. What kind of mod are you thinking about? Whatever it is I would be interested as well.

09-30-2013, 03:39 PM
Waiting for the Yamaha switch mentioned above to come in. Hopefully it is the same (open or closed) as the Moomba switch. I have run many hours jumping 10+ feet in the air on my Wave Blaster in the ocean with it never cutting out unless the lanyard was pulled. The one for their inboard boats looks the same and the same lanyard so I am going to give it a shot.
That is a really bad point of failure, $20 switch to bring the whole boat down.

10-04-2013, 03:50 PM
It would be in the normally closed position because it would function as a supervisory circuit also so any open circuit whether the switch or the wiring will shut down the engine.