Thermostat And Housing

" Joe,

I was looking at th

" Joe,

I was looking at the thermostat housing and wanted to take it apart to check the thermostats and relieve valve. it appears that the mounting screws are corroded. i am a little hesitatant to touch it as i may break the bolts. seems like if i break it it will be pretty difficult to get drill down there to drill and retap them. i tried to loosen the lower cowling hoping that it will drop down but it will not budge enought to clear the thermostat housing screws. here are the

- do they break often ? if i break them how can i get acces to drill and retap it.

-how often do the thermostat or relive valve fail if they are fine now. "

"Ed.... Pertaining to the corr

"Ed.... Pertaining to the corroded thermostat bolts and the problems that might arise. I have removed those rusted, corroded bolts by using odd size (even metric) wrenchs.... anything that would grab the bolt. Of course I had a pencil tip hand held propane torch in one hand and a wrench in the other to do it. And one must be careful as the part between the metal thermo cover and the engine is a plastic like item which will melt/crack, etc.

If a bolt breaks, it's trouble with a capital "T"! It usually results in having to remove the powerhead and the lower pan in order to properly drill out the broken bolt, retap the threads, possibly install a heli coil, etc... a real time consuming procedure.

The relief valves are nothing more than a spring and a nylon beveled tip and they seem to last forever unless the engine overheats bad enough to melt the nylon valve that seats against a rubber gromment.

Some thermostats seem to last forever. Frankly, I'd run the engine and if both banks run at their normal temperture (somewhere around 148°) which is hot to the touch but not hot enough to scald, I'd leave the thermos as is. However, if one bank runs hot, the other cold.... it doesn't leave you much choice but to go the route of changing them.

Joe (30+ Years With OMC)"

" just did that on my 110 john

" just did that on my 110 johnson (1988) broke the botton port side bolt off. tried to drill through the lower cowling. impossible task. it is about 350 to take to good shop (one with own machine shop facilities) to remove powerhead and get out. i found a good shop in pensacola florida that will freshen up the motor for 1200.00
good thing i did, as the piston wirst pin clip had broken and the pin had scored the cylinder wall beyond a normal 30 over. had to have sleeve put in. i guess it is a good thing i elected to spend the extra and have overhaul, as i couldn't have gone much further on that engine. two schools of thought....(1) if it ain't broke, don't fix it (2) my screw up may have saved me a big pain from being broken down 20 miles off shore.

tom/columbus, ga "