Let me start off by saying thank you! This board is a god send!<br /><br />My late 80's Force 125 overheats if pushed past 4,000 rpms for any extended period of time. As a result, I can only go about 34 mph. The boat is an 18ft Bayliner Capri with a 13-19 prop.<br /><br />My troubles all started last summer when I hit a sandbar doing about 48 mph. Very exciting. Needless to say, I sucked in some filth which soon ruined the impeller. The lack of water suction overheated the engine and blew the head gasket. Both the impeller and head gasket have been replaced. For a 15 year old engine, the inside of the engine didn't look too bad.<br /><br />But now, I can't go past 4000 rpm. Assuming its not a water pump problem, what else could it be? Here's what I've come up with:<br /><br />1)I've got some tough filth still cought in the water jscket. How would I go about flushing it out?<br />2)The 13-19 prop is too large for the engine. I did change the prop after hitting the sand bar, but replaced it with what I thought I already had on.<br />3) The fuel-air mixture is too lean causing high combustion temps. How do I adjust air-fuel mixture to know when it is correct?<br />4) I've got a build up of bad carbon letting hot gasses pass the rings. I wouldn't know how to solve this one.<br /><br />Please note that I am new to the boating world and look forward to visiting this board often. Please help me trouble-shoot this problem to get it fixed once and for all.<br /><br />Patrick
