Mercury 35hp twin 67-69 got hot and shut down

[Flaask]

Hey my boatmotor got hot, i was promised that the impeller was change i dident cheak......
So when i was out i lost power and it was super hot so i open up and start cooling it with water the motorblock. So my q is, just trowe it away or try change the impeller and try running it?

 

[racerone]

Compression test first.----Post your numbers.

 

[JDusza]

No thermostat on this engine?
Get yourself an infrared thermometer (they're cheap now) and watch the head temp as you run. Shut it down as you approach 190 F.
Three options for the water pump: failed completely, partially failed or good. If it's partially failed it'll fool you. You'll see some water peeing but the engine will eventually overheat again. You need to watch the head temp to be sure.
Same with thermostat. It's not cleat to me that you have one but if you do, you may see the water peeing with a good water pump but the engine will overheat if the thermostat has failed in the closed position.
With the compression test proving the block and rings are still good, spend the $$ on both thermostat and impeller. They each require grommets and gaskets as well. Probably about $30 to do each. Cheap insurance.
J

 

[racerone]

No thermostat was ever installed at the factory on these engines !!

 

[Texasmark]

When you said you lost power from the engine getting too hot, do you mean the engine seized? If so, you will need an overhaul. BTDT

 

[Flaask]

So a uppdate, the impeller was round so that was the problem, i put everyting back and try starting it and it was rly smooth and ran really well. I went to the dealer got a new one and when i was about to install it, it dident fit, even the mark seems wrong and the size aswell.... So i linked the pic, i guess that this is a diffrent axel and i need a smaller and diff fit impeller maybe you guys can tell

 

[racerone]

Part # of the new impeller ?-----Looks correct to me.-----Vanes on new impellers are not bent like old impellers !!

 

[racerone]

18-3007 or factory 47-89983T ??----Factory is best option in my opinion.----Which one did you order ?-----And yes you have to bend the vanes to get them in the housing !

 

[Flaask]

So more updates it was the right one but i was missing a sprint, i put everyting back aaaand it worked sounds alright well its old so i dont know some sounds are prob someting loose or you know but it works but i think i messed something up with the brackets for the shifter and now i only got Forward and not revers haha but i will make a post about that in the fall for now its running and will take me from a-b so im happy