After pushing to full throttle and once boat planes, the Engine cuts off

1995 Bayliner, 1702 LS: Capri, 70 HP Mercury Force

I had the engine tuned up and gas filters changed because I had noticed that I was not getting the engine performance that I was use to.

After getting the recomended service, I took the boat down to the river to test it out. The engine started up and idled fine in and out of the water( less that 40 total hours on engine). The first thing that I noticed was, when I pushed it to full throttle, that the boat was quickly reaching its speed and the boat was on plane. After the boat planes, at few seconds later, the engine shuts off. It readily starts back up.

I would hate to take it into the shop again due to long waiting lines. One more time and the summer may be over.

Any Ideas.

Re: After pushing to full throttle and once boat planes, the Engine cuts off

Pull the lanyard to kill the ignition, remove the spark plugs to reduce the strain on the starter. Disconnect the fuel line to the carbs and point it into a suitable container. Crank the motor and watch for a strong pulsed fuel stream to diameter of the hose.

Any weakness may be caused by a weak fuel pump or restriction anywhere in a hose,fitting, or even the tank pickup tube and check valve.

The system may be pumping just enough to fill the carbs at idle yet not enough for much load above idle, the motor may simply be running out of gas.

Re: After pushing to full throttle and once boat planes, the Engine cuts off

This thread really should be in the Force/Chrysler forum as it's nopt a Mercury/Mariner.

**************************MOD's, Please move to the Force/Chrysler forum, thanks. ************************************

Re: After pushing to full throttle and once boat planes, the Engine cuts off

Thanks CharlieB

I will follow these steps this evening.

One direction/term need to be clarified for me. Relatively new at boating.

Pull the lanyard to kill the ignition...lanyard

CharlieB said:

Pull the lanyard to kill the ignition, remove the spark plugs to reduce the strain on the starter. Disconnect the fuel line to the carbs and point it into a suitable container. Crank the motor and watch for a strong pulsed fuel stream to diameter of the hose.

Any weakness may be caused by a weak fuel pump or restriction anywhere in a hose,fitting, or even the tank pickup tube and check valve.

The system may be pumping just enough to fill the carbs at idle yet not enough for much load above idle, the motor may simply be running out of gas.

Click to expand...

Re: After pushing to full throttle and once boat planes, the Engine cuts off

Lanyard, a cord attached to a kill switch, to be tied to the operators arm to kill the motor in case the operator falls out of the boat, killing the motor and keeping the boat from circling and chopping up the operator floating in the water.

Re: After pushing to full throttle and once boat planes, the Engine cuts off

Thanks CharlieB

CharlieB said:

Lanyard, a cord attached to a kill switch, to be tied to the operators arm to kill the motor in case the operator falls out of the boat, killing the motor and keeping the boat from circling and chopping up the operator floating in the water.

Click to expand...

Re: After pushing to full throttle and once boat planes, the Engine cuts off

Check the antisiphon valve in the fuel pickup line in the fuel tank. The can get clogged or partially clogged and not supply enough fuel at WOT. Check the fuel tank vent as well.