1987 90hp shutting down, HELP!!

[falkor]

I have a 1987 90hp Evinrude that keeps shutting down after a while. It starts with a continueous beep from the warning horn and it loses power and dies. Could this be a defective thermostat? After it cools it starts back up again only to have the same problem arise. The water pump is new and there is a strong strem running out the pee hole.
Also after some inspection of the motor I noticed the red lever for the choke solenoid was turned the wrong way. Would this adversly affect the performance?
All help would be greatly appreciated. Thanx in advance....Thom

 

[falkor]

Re: 1987 90hp shutting down, HELP!!

I'm bumping this up.
With all the experts on this forum noone can help?
Please, I need some direction,

 

[falkor]

Re: 1987 90hp shutting down, HELP!!

I'd like to thank all the trained proffessionals on this forum for all thier insight and help as to what they surmised was my dillema with my engine (hint of sarcasm) . I cannot believe that a boating forum that gets this many hits doesn't have anyone who will take the time to help out a newbie with a potentially serious problem,YET, they will help people out with problems that have been dealt with over and over again...like flogging a dead horse!!.
For those "trained" pros who might be interested, after I found where the thermostats were located I removed the housing and found one had stuck open and the other was also worn.
Again "thanks" for all your help . This is the number 1 boat forum on the web, and with all your dedication to this board it is bound to be # 2 ....very soon.

 

[aclmvh]

Re: 1987 90hp shutting down, HELP!!

As an untrained professional, but mechanic wannabe with a shop manual, I'll take the first crack. The manual primer lever in the open position would cause rich running, which could cause the engine to die after warmup?..but I don't think that's the overheat problem. I think thermostats. Like my '98 115 crossflow you probably have two thermostats, one for each bank of cylinders. What you describe is textbook tstats stuck closed. At startup, they are closed to enhance engine warmup, and once the engine reaches around 144 degrees, they should begin to open, allowing water into the cylinder water jacket for cooling. If they stick closed, you'll still get a pee stream....that means the impeller is working.....but that doesn't mean the water is getting to the cylinders where the heat senders are located....hence the overheat warning (I'm assuming the heads are too hot to touch). The tstats are usually located on the aft of the motor between the cylinder banks- mine are at the bottom. Sometimes you can tap the housing to break them loose, or you can high idle the engine above 2000 very quickly and they might open. Whatever, don't run that motor after you hear the heat warning!

 

[chubcobear]

Re: 1987 90hp shutting down, HELP!!

I have a 1987 90hp Johnson crossflow, and I agree. It is exactly how they act when the thermostats are stuck closed. Check there first. Don't run the engine. Thermostat kits are available here on iboats.

 

[falkor]

Re: 1987 90hp shutting down, HELP!!

Thanks for the replies guys. After forking out $50 CAN. for a tstat kit and turning the red choke tab all the way clockwise she is back running like a new motor...Thanks again.