I just purchased a 1984 Cruisers Inc 266 Vee Sport with twin Mercruiser 260's and Alpha drives. I do not have access to the serial numbers at the present time, but I know they are both 63xxx something. The hour meters show about 1100 hours. At some point, the starboard engine was replaced. As usual, according to the previous owner, everything works and operates perfectly - I live in the real world - I knew going into this that this was not the case. I'm happy with what I bought and the purchase price was right. I'm not a stranger to boats , so some repairs do not bother me.
I started with a basic tune up and set everything to factory specs. I discovered a broken exhaust valve spring on the number seven cylinder on the starboard engine. I repaired this and the motor ran perfect with the exception of never warming up. I purchased two Mercruiser thermostat kits from the dealer and installed them according to the printout he gave me. I've attached a copy of it. The engine now runs perfect - about 140 degrees at an idle, between 150 and 160 under load. So far, so good.
On to the port engine. It was doing the exact same thing as the starboard - never warming up. I installed the thermostat exactly like I did in the starboard engine and this engine now idles at about 165 and steady creeps up under load. I backed out of it when the gauge hit 200, watched the gauge climb to 220 at idle, then rapidly cool down to 165. I started looking in the manual and see the thermostat is installed differently than the printout the dealer gave me. Again, I've attached a picture from the manual.
My question is which one is correct? I'm leaning toward the printout, because that's the way the old stats were installed. But then again, I'm dealing with a nearly 30 year old boat that anyone could have done anything to at one time or another. I don't want to over-think this problem - I just want to get it operating correctly before I have to put it away for the winter.
Any and all advice is appreciated.
Mark
I started with a basic tune up and set everything to factory specs. I discovered a broken exhaust valve spring on the number seven cylinder on the starboard engine. I repaired this and the motor ran perfect with the exception of never warming up. I purchased two Mercruiser thermostat kits from the dealer and installed them according to the printout he gave me. I've attached a copy of it. The engine now runs perfect - about 140 degrees at an idle, between 150 and 160 under load. So far, so good.
On to the port engine. It was doing the exact same thing as the starboard - never warming up. I installed the thermostat exactly like I did in the starboard engine and this engine now idles at about 165 and steady creeps up under load. I backed out of it when the gauge hit 200, watched the gauge climb to 220 at idle, then rapidly cool down to 165. I started looking in the manual and see the thermostat is installed differently than the printout the dealer gave me. Again, I've attached a picture from the manual.
My question is which one is correct? I'm leaning toward the printout, because that's the way the old stats were installed. But then again, I'm dealing with a nearly 30 year old boat that anyone could have done anything to at one time or another. I don't want to over-think this problem - I just want to get it operating correctly before I have to put it away for the winter.
Any and all advice is appreciated.
Mark
