T-stat on 50HP Mercury

[jdupree]

My father in law has around a 1991 Mercury 50hp. Noticed that at wot motor is cooling fine and "peeing" strong. At idle the motor starts running hot and the "peeing" is weak and sometimes stops. Does this motor have a t-stat and where is it located. Does this sound like a water pump issue?

 

[andy6374]

Re: T-stat on 50HP Mercury

Type the serial number into www.mercurypartsexpress.com

See if it has a tstat and/or a pressure relief valve. It sounds like the poppet isn't seating itself at idle. The tstat would be located at the top of the cylinder head and the poppet valve would be located under the ignition plate under the switchbox.

However if you or your dad doesn't know when the last time the waterpump, tstat..etc were changed it would be good idea to do all in one swoop.

 

[jdupree]

Re: T-stat on 50HP Mercury

Thanks Andy. I did notice that near the top of the head on the star side there looks like a little round frost plug that is silver. It looks like that it would pop out. Is that what you are talking about?

 

[andy6374]

Re: T-stat on 50HP Mercury

If there is a tstat, there will be a housing covering it.

What is your serial #

 

[jdupree]

Re: T-stat on 50HP Mercury

Andy,

He said that the engine is a 1989 and the model # says model 50 which I assume is 50hp. If this helps please let me know. I need to know if it has a t-stat or not. Thanks,

John

 

[andy6374]

Re: T-stat on 50HP Mercury

It doesn't look like it has a tstat.