Bertram33 User Forum

When I was winterizing my 5 HP Merc I noticed that the water pump was just trickling water out...not the steady stream I normally see. Anyone know where I start looking ? There must be a restriction somewhere, but I've never dug into these things before. Rick Ticket 85 SF Merc 454 MPI's Falmouth, MA

Rick, It's probably one of two things, the water pump impeller or sometimes if the engine doesn't get used much and has salt water setting in it for a long time, the aluminum will corrode and cause a gel like substance to build up in the water passages. If that's the problem it you can take the head off and clean it out or , what I'd do first is run it with a mixture of water and muratic acid.The acid will clear it out nicely and aluminum is very resistant to it.Steel hates acid but aluminum doesn't have much trouble with it.

Thanks Frank, That's got to be it because it has been sitting since the end of July. I'll give it a try. Rick Ticket 85 SF Merc 454 MPI's Falmouth, MA

Take the small hose line from where the water comes out for the tell tail water from inside the engine cover it may have a small clamp and just blow in it sometime you get debri in the tube slowing the flow out the back.

A couple of years ago my 10hp 4 stroke suddenly stopped pumping water. I hit the exhuast outlet pretty hard with a hose and have not had a problem since.

Ya I should have mentioned that as the first thing to try. It won't hurt it to blow air or water back through the other way first to see if something will blow out. My Suzuki 40 just had something blocking the pee hole and I had to remove the end and tap out some chunks of guk.