Merc 197? 4hp

[cookski]

Just had the impeller replaced but there is still nothing coming out of the **** hole and the motor overheats within minutes. Serial number is 9208691, should be about 1978 or so. Any help or advice is greatly appreciated.

 

[SpinnerBait_Nut]

Re: Merc 197? 4hp

That would be a 1979 model and my best guess without knowing anything else would be that the impeller is in backwards.<br /><br />If it is, it will not pump water.

 

[Chinewalker]

Re: Merc 197? 4hp

There is no forwards or backwards on a new impeller. Installing one with the vains reversed will be righted the first time the motor is started. More than likely it is sucking air somewhere in the system, there is a blockage or the water tube wasn't properly seated in the pump housing. The plastic grommet at the top of the water tube is also a common culprit. Compressed air blown up through the water tube can tell you a lot...<br />- Scott

 

[Paul Moir]

Re: Merc 197? 4hp

My 4hp Mercury gnat (2 cylinder) has no tell-tale. Intead you get a mist from the many idle relief holes drilled in the leg.<br />I agree with Chinewalker completely, especially about the water tube grommet. It was almost entirely blocked on mine.