1980 Merc 50 power loss under stress

[EMSman]

I have a 1980 Mercury 50hp that is losing power when hitting waves or during a tight turn. While I understand some power loss is normal, since it being put under a strain, but the loss is so great it sounds like the engine is going to die. It idles and runs great otherwise. It easily will plane my boat and will run at max rpm, unless put under this stress. Any thoughts / suggestions would be appreciated.

 

[roscoe]

Re: 1980 Merc 50 power loss under stress

What are your wide open throttle rpm's?

 

[andrewkafp]

Re: 1980 Merc 50 power loss under stress

I know these may be silly questions.. but are you sure it's not either scraping the bottom or the prop lifting out of the water whilst riding the wave ? Is the water shallow ? <br />I have experienced both these things and thought I had engine problems

 

[poeker1]

Re: 1980 Merc 50 power loss under stress

Hey EMS<br /><br />You posted on my problem, but let me tell you what happened to me. The first time I put my boat in the water, it did the same thing. On smooth water it runs OK, but on rough water it wants to die. My solution was this: I replaced the choke return spring on the carburator. Every time the motor bounced the electric choke solinoid got "stuck".<br /><br />Hope it works<br /><br />Paul

 

[EMSman]

Re: 1980 Merc 50 power loss under stress

Thanks for all the suggestions. The lake I am using is >20 feet and it does it at all parts of the lake. I'm not sure what my wide open throttle rpm's are, but I am pretty sure it's close to max when going straight, without a strain. The choke return spring idea is great! That makes a lot of sense. Now that I think of it, that may be my problem. Thanks again for all the help!<br />Matt

 

[EMSman]

Re: 1980 Merc 50 power loss under stress

I called the local boat part store. They said there is no return spring for the 1980 50hp engine. I looked at the choke solenoid and it is pretty strong. I don't think it is a choke problem, unfortunately. That would have been an easy fix. Any more ideas?<br />Thanks!<br />matt