Engine shuts off at high speed.

[siaboat]

Greetings,
I have a Mercruser 140 , 3 Liter,
It starts well , runs well but sometime whe I put it on hight throtle after about 5 min. drive it will shut off as if the coil is burnt. Very quickly goes dead.
then it will take an hour or so of fooling arround and it will start again.
Can anyone tell me what it could be. It dose not look like it is gas problem. It will crank over so It can not be battery, Can it be condenser, point, or Coil.
Is there a shut off switch somwhere?

Thanks a million for your help

 

[Chris1956]

Re: Engine shuts off at high speed.

You might repost this in the I/O forum. Add the year of the motor and whether it is carb or EFI.

Sometimes the antisiphon valve on the fuel pickup will get clogged. This allows the motor to run at low speed, but starves the motor or fuel at high speed.