Hi everyone I hope you can help me out. I recently purchased a bass boat with a 86 mercury black max 135. The first thing i had to replace was the stator and did a total rebuild a fuel system including rebuilding of the carburetors. I had one day of good fishing with no problems. And the next day it started overheating, according to the temp gauge anyways, it runs in the middle of the gauge while ideling put it on plane said and the temp goes up quick . So We replace the water pump completly, new poppet valve including both metal plates. Replaced both thermostats, all water lines are clear i have good water flow and the cooling system is functioning like clock work.
So i take it down the lake about 45 mph the overheat alarm goes off, i take a IR temp gun and the hottest spot i can find on the whole block is 164 deg and the water from the tell tale is 140, the stats are working just like they should. So frustrated i installed water pressure guage and printed a flow chart to compare to and i am way out there. 12 psi at idle and pegs the needle at 30 psi above 2500 rpm.
I know there are a lot of smart folks here and sure hope someone knows a solution, thanks in advance
Bud
UPDATE
Well my overheating issue continues.
Here's a list of things we have done
1. Complete water pump rebuild
2. New water tube and seals including power head seal
3. Power head and exhaust plate gaskets [ found power head gaskets had holes]
4. New head gaskets [ heads were clean and flat with straight edge ]
5. New water jacket gaskets [ water jackets were clean ]
6. Exhaust divider plate gaskets replaced.
Water pressure still remains high [ idle 5-10 psi ] running above 2500 rpm it pegs at 30 psi ]
We found no obstructions anywhere in this motor and probed and blew compressed air through every hole. This motor was and is very clean.
I am at my end with this motor and so discouraged, I am tempted to just part it out and move on and hopefully find another motor next year.
I know you guys have dealt with these issues on the forums so many times and probably sick of overheating threads, I have tried everything i have read about and nothing seems to work. So if you folks can think of anything to try i would be very appreciative.
So i take it down the lake about 45 mph the overheat alarm goes off, i take a IR temp gun and the hottest spot i can find on the whole block is 164 deg and the water from the tell tale is 140, the stats are working just like they should. So frustrated i installed water pressure guage and printed a flow chart to compare to and i am way out there. 12 psi at idle and pegs the needle at 30 psi above 2500 rpm.
I know there are a lot of smart folks here and sure hope someone knows a solution, thanks in advance
Bud
UPDATE
Well my overheating issue continues.
Here's a list of things we have done
1. Complete water pump rebuild
2. New water tube and seals including power head seal
3. Power head and exhaust plate gaskets [ found power head gaskets had holes]
4. New head gaskets [ heads were clean and flat with straight edge ]
5. New water jacket gaskets [ water jackets were clean ]
6. Exhaust divider plate gaskets replaced.
Water pressure still remains high [ idle 5-10 psi ] running above 2500 rpm it pegs at 30 psi ]
We found no obstructions anywhere in this motor and probed and blew compressed air through every hole. This motor was and is very clean.
I am at my end with this motor and so discouraged, I am tempted to just part it out and move on and hopefully find another motor next year.
I know you guys have dealt with these issues on the forums so many times and probably sick of overheating threads, I have tried everything i have read about and nothing seems to work. So if you folks can think of anything to try i would be very appreciative.
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