mecr v6 over heat ,in midrange

[latitude ajustment]

ok been a marine tech for a long time ,over 35 years, got a late 80's v 6 thats overheating in mid range idle runs cool ,high speed runs cool , not setting off the buzzer , but gettin there,, the owner blew up his powerhead last year a 150 hp , oil line broke ,end of story , he bought a 135 hp same year so I swapped power heads , after that I cant get this thing to run at the same temp Like I said runs cool low speed and High , round 3000 it will start to over heat done everthing I can think of ,, he bought a boat motor and trailer for 1,500 bucks so Im thinkin the previos owner had the same problem ,

I have done all the regular stuff water pump kit, stats , in and out , and gutted .. neat trick in saltwater,,,, popet valve ,,, carbs compession, ignition , sink and link , still running the same prop , not commig up to the upper end of the rpm's but close,, I realy dont want to start tearing this apart if I dont have to ,,,, anybody have any Ideas , Thanks

 

[CharlieB]

Re: mecr v6 over heat ,in midrange

Does it still have the idle stabilizer module?

Remove it and 'accidently' drop it overboard, preferably somewhere so deep it can never be found.

Double check WOT Timing, reset to no more than 23 degrees cranking.

Triple check timing lever is free and moves well with throttle lever to its wot timing stop.

 

[latitude ajustment]

Re: mecr v6 over heat ,in midrange

give the stabilizer a float test ,,, if its good it floats ,if its bad it sinks why ? is it messin with the timing ,,, Im going to have to start all over again , boat is comming out of storage this weekend done the timming half a dozen times static and in the water been over and over this thing missin something , ,,,, u seem to think its got to do wth the sink and link , timing being off , Thanks