Merc 9.8hp cooling issues

[joblo33]

I recently bought 3 9.8hp Mercs, the oldest being a 1978 and the newest a 1982. They were all sitting in a yard for the last 5 years and seem to all have the same problem; they blow exhaust out the pisser when running. I took the exhaust cover off one of them and the gasket looks shot. Is this a common problem with these engines? If so do I just buy new gaskets for each motor or is there a better way to prevent this from happening again?<br />Thanks,<br />Eric

 

[Chinewalker]

Re: Merc 9.8hp cooling issues

Have you replaced the impellers in them? New waterpump impellers are a must on those little Mercs. Also, a common problem is the nylon spacer at the top of the water tube often melts shut. Checking it would require pulling the powerhead. I usually leave that as a last resort if the motor isn't pumping after checking the easy stuff.<br /><br />- Scott