Power problems

[jwtx]

GT150. Model# J150STLESB.

Fixed the tach problem - Loose connection. Took a while to find

New problem -

Still seem to have an electrical grimlin in the motor. Run the motor above 5000 rpm for more than a minute or so and it shuts down. Full throttle is 5400RPM. Totally looses power. The electrical kind. It is like you pulled the kill switch. No buzzers or warning of anykind. When you try to recrank it you have nothing. No starter no fuel primer nothing. The gauges on the dash work but that is it.

Troubleshooting so far -
Stranded in the middle of the lake I was limited but... I checked and both thermastat housings where warm to the touch but not too hot. Motor was not froze I could turn the flywheel by hand. Watched the starter as I hit the key and nothing happens. Listened for the fuel primer click and again nothing. Left the cover off while I trolled and fished for an hour or so. Tried it again and it started up. Took off and things were good until it shut down again. I did figure out if you keep it below 4000RPM's you can go farther.

Any help would be grateful.

[Danrude]

It sounds like you have another bad connection, somewhere between the switch and the start selenoid. It sounds as if a connection is loose and is opening when it gets hot. I would start with the ignition switch and work toward the selenoid. there is the posibility the switch or selenoid could be bad as well.

[ChampioNman]

Check all of your engine grounds at the starter and also at the battery, get rid of any and all wing nuts and replace with nylon insert SS hex nuts. Also try this if it happens again, turn your steerwheel in the opposite direction it is in when the problem ocurrs, It may be the harness it self.

[jwtx]

OK. I'll go back through them. I originally found the starter loose. The ground actually goes through the starter, so I was loosing ground. The problem I am having now seems to be heat related. If you let it cool off it will start back up. It can take up to an hour or more.

[jwtx]

Update - I checked all the connections again. Took it out to the lake with a volt meter. When the motor shut down I checked voltages. The primary "red" on the starter silinoid had 12V. One the ignition wires there were no voltages on the yellow, yellow/gray, ect. This is with the key on. I have checked the wires before launch with the key on and there was voltage. I waited 15-20 minutes with the cover off and tried it again. Motor turned over and I had the voltages again.

Things I noticed. Seems if I keep the motor RPMs below 4000 things are OK. At 5000-5400 it only will run a minute or less then shuts down. When it starts shutting down it now drops RPMs almost like someone is pulling back on the throtle. But you can here the motor growning as the butterflies are still open.

When the motor is running is seems to not have a great hole shot. Seems like has lost a lot of power. Once on plan and RPMs are up seems to be ok till shutdown.

I pulled the plugs and all are running rich. The right bank worse than the left but not by much. I have been through the carbs and I believe they are ok. These carbs are not adjustable. The metering is set at the factory.

Therories: Could the ignition system be causing the problem? Could week spark be causing a rich condition? If so what di I need to look at? Could it be the power pack?

Thanks

[jwtx]

Any ideas from the pros on what could be going on? Why I am loosing voltages on the yellow and yellow/gray wires?

[Danrude]

I do not have the wiring diagram for your setup but I will tell you what I can from memory. Testing the start selenoid, look at the small terminal(s) you should see an "S" stamped beside one. That terminal should have 12V on it when you turn the key to the start position. If it is there and the starter does not engage suspect the Solenoid, if it is not, suspect the key switch.
At the key switch when you turn the key to the on position it applies the 12v to the engine to run the different systems. without a drawing I am not sure where it terminates at the engine, you will need to determine if the 12v is being applied to the engine. if not suspect the key switch.
I suspect you are loosing the 12v to the engine when it shuts down.
Such as it is I hope this helps you in troubleshooting your problem.