Home › Forum › Ask A Member › 9.9/15 impeller housing tricks? › Re: 9.9/15 impeller housing tricks?
Several more points. First on larger OMC engines the pisser doesn’t indicate anything , but that the engine is pumping water! That may come as a shock since Merc is opposite. I am not positive OMC small engines are that way or that it has always been that way. JohnnyRude those manuals I sent you have a water flow diagram in the rear for each model. Blue is cold water red is hot. Very helpful, take a look.
The hole that Frank R told you about on the 20hp fills the top driveshaft cavity with water making a seal so exhaust gases are not drawn into the pump. Air pulls into a pump easier than lifting water.
The copper tube needs to be as long as it is up to the powerhead of the engine, that’s why I said bend it away from you (or you will get an ear full). I figured you would take the prop off since that has nothing to do with pumping water, not like the old days!
Just put a long bolt in the back of the gearcase to hold on to or bolt you a handle to it.
Dan in TN