flapper question

[billy boater]

i have a 2.3 ford in my boat with a omc drive and have been trying to chase down a overheating issue for quite some time i pulled the exaust elbow off and saw the flapper was missing. im gonna replace it but was wondering if that could contribute to my problem. it only overheats at idle or going really slow. if the r's are above 1500 or so it runs cool as a cat.

 

[searay3]

Re: flapper question

Inspect the raw water pump. The symptoms reflect an ineffecient pump. Some guys have left the flappers out. I don't believe that would cause your overheat. There is a concern of backwash (slowing down rapidly) going up the exhaust. If you slow gradually and don't cut the engine before you have stopped, shouldn't have an issue without them.

 

[billy boater]

Re: flapper question

that was kind of a dumb question for me to ask but im running out of ideas. i know its not the raw water pump cuz i have replaced it a number of times along with all new gasketts housing back flushing the system and all that would be involved. i wish it was that easy. i always get these weired problems that take forever to figure out.