86 Mercruiser 260 running warm

[samm835]

I recently picked up a 268 Sea Ray, she has a merc/260. The impeller was just replaced but the motor is running hot. Its a closed cooled system, what would be a good thing to look at? The water pump? I've replaced one on other motors....but never a closed system, is it more difficult? Let me know thoughts.....

 

[alldodge]

Being an 86 it might have a belt driven water pump which would be located on the starboard side of the motor, down low. If this is the case, replacing the impeller is only as hard as it is to get to. Being an overheat problem, this is where I would start.

Next thing would be to back flush the raw water hoses leading to from thermostat housing. Check both sides of the power steering cooler for pieces of an old impeller, then check/replace thermostat

 

[samm835]

I didn't realize this motor had an impeller in it, I thought only one in drive, and a water pump. Im ordering a book/manual

 

[alldodge]

I'm not sure if your motor does or does not have the belt driven pump, hence the sort of question I was asking. Most boats with a V8 and Alpha drives, had the impeller removed from the drive and had the belt driven pump installed. The Alpha drive impeller does not move enough water for a closed system.

 

[samm835]

So if its belt driven, I should be able to loosen belts, pull casing off to check impeller fairly easy if its like the water pump correct

 

[alldodge]

So if its belt driven, I should be able to loosen belts, pull casing off to check impeller fairly easy if its like the water pump correct

If the pump is there it would be something like the one in the link below
http://www.mercruiserparts.com/bam/subassembly/31576/906/130

 

[samm835]

Anyone know off hand which thermostat I should be getting for this 1986 260 merc?

 

[alldodge]

Anyone know off hand which thermostat I should be getting for this 1986 260 merc?

That would be 140 degrees