Thermostat Location on 1993 Mercury 2 stroke/ 4 cyl (115Hp)

[RAZLEO]

I have the 1990-1993 3-275HP Mercury Outboard Shop Manual and there is no mention of a thermostat? Does this mean these engines did not have one? My engine overheat (?) alarm is going off

 

[Dave1027]

Which motor are you asking about? 115 hp or a 3 - 27 hp? The 115 hp has a thermostat. It's on cylinder head/cover top left.

 

[RAZLEO]

Which motor are you asking about? 115 hp or a 3 - 27 hp? The 115 hp has a thermostat. It's on cylinder head/cover top left.

115HP. Thanks ever so much! Strange there is no mention of it in manual?

 

[Dave1027]

Does your boat have a working temperature gauge?

 

[RAZLEO]

Does your boat have a working temperature gauge?

Unfortunately it does not have any temp gauge. It's a 1990 Sea Pro that I just bought recently

 

[Dave1027]

Unfortunately it does not have any temp gauge. It's a 1990 Sea Pro that I just bought recently

Just keep in mind, these motors are more likely to have the warning module go bad than the thermostat. Have you checked the water impeller? That is also more likely.

I see you corrected your initial post. A 3 -275 HP manual is way too generic. If you are planning on keeping that motor, you should invest in a Mercury shop manual that is specific to your motor.

 

[RAZLEO]

Thank you so much Dave1027. You have been a great help! The warning horn is not on all the time...........just intermittently. Do I need to take it apart to check the impeller?

 

[Dave1027]

Thank you so much Dave1027. You have been a great help! The warning horn is not on all the time...........just intermittently. Do I need to take it apart to check the impeller?

To check/replace the impellor you need to unbolt and remove the lower unit. The process should be in the manual. It is in the Mercury shop manual. There are probably you-tubes that show you how.