50hp Mercury - Will only operate at low RPM, stalls frequently...

Joined
Sep 4, 2009
Messages
60
Hi!

I purchased a '67 Renken boat and it came with a 1981 Mercury 50hp, 4cyl, manual start. It did not run, and the previous owner told me that it needed a high-speed stator. (The marina verified this.)

I ordered the stator and when it arrive it looked very different from the one that was under the flywheel. The old stator was a little metal ring with two coils on it and four wires going to the switchbox.

The new stator was much thicker, no coils were exposed, and it had about 10 magnets around it. I called the store and we double-checked part/serial numbers and the numbers matched.

The place where I bought the stator said that Mercury had put the wrong part in the right box. So I've been sitting for over 1 month waiting for Mercury to ship me my little metal ring with the two coils.

Finally, I did some checking online, and by entering the part number I needed, I found several places selling the stator I had received. So....I thought, "this HAS to be the right one." The pictures and numbers matched the one I had received, and they said that it was for my motor with a manual start. (I'm desperate and Mercury isn't exactly on the ball!)

I put it in to see if it would fit, reassembled the motor, and walla, it ran.

Took it to the lake tonight and it wants to die as soon as I put it under a load. If I CAN keep it running it will only run at very low RPMS (my boat plowed the water - that's all the faster it would go.)

The carbs were rebuilt last fall, and all the fuel lines look fine. Maybe it was the wrong stator after all? Maybe it's something else? The trigger? Any ideas/suggestions would be appreciated. :)
 

starcraft1982

Petty Officer 1st Class
Joined
Feb 7, 2010
Messages
277
Re: 50hp Mercury - Will only operate at low RPM, stalls frequently...

Did the stators wires come out at a different angle than the original?I read a post a while back where this happened to someone and the wires,by coming out at a different angle,caused them to get rubbed by the flywheel.Just throwing it out there to check out as i remembered reading about it.Not saying it is or isnt the problem.good luck
 
Joined
Sep 4, 2009
Messages
60
Re: 50hp Mercury - Will only operate at low RPM, stalls frequently...

I don't think that is the problem, but I'd be open to checking. The wires come out well below the flywheel.
 
Joined
Sep 4, 2009
Messages
60
Re: 50hp Mercury - Will only operate at low RPM, stalls frequently...

I checked the wires and they are fine.

In my manual it says to check the stator by doing in OHMS test on the stator leads. Should they be disconnected from the switchbox or not? I've tried it with them on the switchbox but the readings are weird. Of course, this isn't the stator that originally came with the unit.

I may test the trigger but I'm not sure if I should disconnect the leads from the switch box or not. (Would this be something a bad trigger could cause??)

Thanks for your help
 
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