Mariner that gets hot

[jami0035]

I have a 1981 Mariner that runs well until the water from the outlet pipe slows then stops. Then there is a large cloud of steam and the motor sounds unwell. I assume there is a deposit of rubbish or crystals in the powerhead that occludes water flow. What options exist to clean this out without removing the powerhead which I am scared of snapping a headbolt?

 

[andrewkafp]

Re: Mariner that gets hot

Welcome to Iboats fellow Aussie. You have discovered the best OB site around.. <br />It sounds like your water pump impeller needs replacing. DON'T run it til it sounds "Unwell" as you may damage the top cylinders through lack of cooling. When was the last time the impeller was changed?, as it sounds like it has "Taken a set" (This is a US Term that means it's permanently set is a bent position).

 

[jami0035]

Re: Mariner that gets hot

Thanks Mate! I replaced the impellor, water pump housing, grommets, gaskets etc only two weeks ago incase there was a poor water feed problem. The water pressure when cold is now pretty good.

 

[erniex]

Re: Mariner that gets hot

You might try backflushing it through the tell-tale with water or compressed air if it's stopped up. This happened to me on the lake and I discovered that I had spun the impeller! Driveshaft was worn enough over the years that the play allowed the shaft to turn at high RPMs w/o spinning the impeller. Could pull the lower unit and connect downpipe to a water hose and try to flush it also.