89 J50 ran hot

[ob15]

1989 J50 J50TLCEC<br /><br />I just replaced the lower unit with a rebuilt one. It ran fine in the driveway on muffs after installation (probably around 15 min). Took a little cruise on Sunday and mostly putted around. The motor tell tail was nice & strong the whole trip. When we got back to the ramp the motor would not idle. The spark level had slit where the idle stop screw is and I couldn’t adjust the idle. I am ordering a new lever today. Will do a link & sync after installation.<br /><br />Anyway, when I was flushing the motor after the trip, the tell tail wasn’t very strong (had the hose on full) and the overheat alarm went off. I shut the motor off immediately. I noticed that the tell tail water was very warm and the exhaust water felt ok. Any ideas on what to check? I will check the impeller to see if it was installed correctly and that the key is not sheared. I will also be replacing the t-stat. Do you think the head gasket is ok? It sounds like there may be an obstruction in the water passages if the impeller is ok.<br /><br />Thanks again.

 

[WillyBWright]

Re: 89 J50 ran hot

Concentrate on the impeller first. That's usually the weak link. They get hard over time and can break when returned to service. Sometimes right away, sometimes after a few hours of running. It usually starts out as a small crack in the rubber that gets larger and larger from flexing until it finally breaks off. Make sure all of the chunks are accounted for. Some may fall into the water intake area, some may pump into the motor and cause a blockage.

 

[ob15]

Re: 89 J50 ran hot

Thanks Mr. BWright. I was thinking that but also everything on the lower unit is new. That's why I asked a bunch of questions. I thought it was kind of weird that am impeller would go after only a few hours of use.