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Mercury 4.5 won´t idle

R

rallypack

New member
Hi guys

New member from Sweden here.

I recently bought a 4.5 hp Mercury from about 1980. The previous owner said that the engine had died and was unusually hot. I changed the water pump immediately because the old one was in pieces. After this, I can start the engine but it only runs at high revs. Once you try to get it down to idle it dies. Could it be that head gasket is bad? Could there be something else wrong?

Really appreciate if I can get help with this.

Thanks!
 
..."Could it be that head gasket is bad?"

There is no head gasket on that motor--what you see back there is merely a water jacket cover. I suspect the carb needs a rebuild.

Jeff

PS: Those run so well it changed my stubborn mind on single cylinder outboards.
 
fastjeff said:
..."Could it be that head gasket is bad?"

There is no head gasket on that motor--what you see back there is merely a water jacket cover. I suspect the carb needs a rebuild.

Jeff

PS: Those run so well it changed my stubborn mind on single cylinder outboards.
Click to expand...

Thanks for your answer fastjeff!

Might be my translation that´s a bit wrong. I mean the gasket between the cylinder and the head. There must be one? All my other mercs have one. I thought since the prevoius owner overheated the engine it could be that the gasket is damaged.

I tried to remove the carb but it was harder than I thought....

Should I do a compression test? Could the compression be bad due to the overheating?
 
The end of the cylinder is closed--no cylinder head in the usual fashion.

Overheating will destroy the rings and the compression. Test it before you go any further. Easy to hone and re-ring the motor, and the carb comes off easy with the power head off!

Jeff
 
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