1981 80hp merc will not run at high rpm.

kfreund

Recruit
Joined
Oct 27, 2003
Messages
2
Can someone please help me with my dilema. I have recently purchased a boat with an 80 hp Mercury motor (1981 serial #6080235). It runs and starts fine for the first 5 minutes. It then will only run at half throttle. If you pump the throttle really fast about 3 times it will occasionally run for another 100 yards or so at high speed. I have changed the feul line 3 times, changed the gas tank once, and rebuilt the feul pump and carburators. I have taken it to a shop and they say "its fine". But they dont have the ability to rrun it at high rpm for more than a few seconds. They suggest changing the switchbox and trigger. I am good with that but why would it run good if I pump the throttle very fast a few times if it had an electrical problem? Could one of you experts help me solve my dilema?<br /><br />Thank You very much
 

rickdb1boat

Supreme Mariner
Joined
Jan 23, 2002
Messages
11,195
Re: 1981 80hp merc will not run at high rpm.

Pump the primer bulb when it does this and see if it helps. Also, check fuel tank vent for obstrutions or leave the fuel cap loose and try it..
 

kfreund

Recruit
Joined
Oct 27, 2003
Messages
2
Re: 1981 80hp merc will not run at high rpm.

I have tried to pump the ball with no success. I have also checked the vent and even losened the gas cap. Do you have anymore suggestions?
 

The Marine Doctor

Commander
Joined
Jul 25, 2003
Messages
2,177
Re: 1981 80hp merc will not run at high rpm.

Try running it without the hood on. Try to be careful and not let water at the carbs.<br /><br />TMD
 
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