1981 Merc 150 OB, misses BAD when under a load(M)

[getlo]

Serial #6552003 I have had a new Stator put on recently also. (mine had melted) ANyhow, the Motor starts like a dream, idles wonderful, runs slow wonderful, but when you plain out...after about 2 minutes of running, the motor starts hesatating, and trys to quit. I also had a new water pump put on recently. PLEASE help. The boat that its on is a 17 ft Hydrasport fishing boat. Thanks!!

 

[Hooty]

Re: 1981 Merc 150 OB, misses BAD when under a load(M)

Howdy Tonya and welcome to iboats.<br /><br />When the engine is starting to miss, bump the choke real good and see what happens. If you've got carburetor problems, you should hear an improvement in the way the engine runs. If it just floods out and dies, I'd guess an ignition problem.<br /><br />c/6<br /><br />Hooty

 

[getlo]

Re: 1981 Merc 150 OB, misses BAD when under a load(M)

Thanks! I will try the choke, but how could it be in the ignition? Doesnt seem like that is what it could be by the way it acts, but I dont know that much about OB's.

 

[roscoe]

Re: 1981 Merc 150 OB, misses BAD when under a load(M)

Thats simple. Its because outboards are weird.<br />What looks to be the cause, usually isn't.

 

[jim dozier]

Re: 1981 Merc 150 OB, misses BAD when under a load(M)

It could be a heat sensitive ignition part that starts to fail when it gets good and hot. However, I bet on carb problems or some other fuel starvation cause.<br /><br />Have you verified that the engine is not overheating when the problem starts?

 

[Reel Appeal]

Re: 1981 Merc 150 OB, misses BAD when under a load(M)

Tonya,<br /> I had a very similiar problem with an '86 Merc.175.The stator/trigger was replaced also.Problem seemed better but still there.This motor would run great at lower rpm's but did not want to get up on plane.I opened up all the carbs only to find junk/debris in them.So after a $500+ bill(and almost a month in the shop) for the stator/etc. work,turned out that was the problem.

 

[G DANE]

Re: 1981 Merc 150 OB, misses BAD when under a load(M)

Hi Tonya<br /><br />Are you sure you have a good unrestricted flow from your tank - it could sound like it isnt ventilated enough or you have som restriction. If possible try someones portable tank, and line - if problem still occurs, try to press primerbulb. If this helps, rebuild your fuel pump. If problem is gone with the tank change, you will have lines sucking air, or restriction in pickup, or bad ventilation.