8hp Mariner Over Heating

[sleeman]

Hello. I have a 1980 8hp Mariner outboard that starts great and after 4-5 min gets very hot and sluggish. I finally got the lower unit off and the impeller seems to be fine. Looked in my manual and it does't say much. Please help. Thanks, Chris

 

[Mariner60_hp]

Re: 8hp Mariner Over Heating

Could be a bad thermostat. Post model and serial #

 

[sleeman]

Re: 8hp Mariner Over Heating

1980 8hp Mariner, Model# 8B, Serial # 677S002789.<br />The engin was purchased on 6-16-79. Any help would be greatly appreciated. Thanks

 

[Mariner60_hp]

Re: 8hp Mariner Over Heating

This link shows a breakdown of the crank case and head. It also shows the Thermostat. You may try pulling the cover and checking the condition of the thermostat. It may need cleaning or replacing. You can also try running it without the thermostat and see if the problem persist. If it does then there is probably a blockage in the water pasage. Also if the impellar has not been changed it is always good practice to replace it. http://www.dougrussell.com/partscat...=7,8,13,1,4,5,15,3,9,17,18,11,16,6,20,2,19,12 ,14,10

 

[sleeman]

Re: 8hp Mariner Over Heating

Thanks for the info. I will remove the thermostat this weekend and see how it runs. Thanks Again

 

[sleeman]

Re: 8hp Mariner Over Heating

I finally got around to removing the thermostat to see if this was my problem. It ran great for about 3-4 min, then heated up and got slugish. I shut it off and let it cool for an hour and it started right up. Any other ideas...Please help

 

[Fouled Plug]

Re: 8hp Mariner Over Heating

Do you have any water flow from the telltale or exhaust?

 

[sleeman]

Re: 8hp Mariner Over Heating

Normally, 2 streams of water squirt from the back side of an outboard motor. I can't see where they would come from on this unit?