mercury cruiser 170 hp temp

[southwest395]

I have a 1987 mercury cruiser 170 hp I/O what is the normail operating temp and rpms for this motor. Also if i dont run the blower motor it doesnt get over 175 in temp but it will just crank until the motor cooles down. Any ideas.

 

[Oshkosh1]

Re: mercury cruiser 170 hp temp

Assuming you have a 140deg T-stat, you should be running about 30 deg warmer, or around 170...so 175 is normal.

When you say "blower", that has no bearing on the temp of the engine, it's just used for exhausting fuel vapors while idiling or prior to startup after sitting for a period of time.

As far as the hard starting, it could be a myriad of problems depending on the age/condition of your ignition, and fuel components. Culprits could be plugs, wires, carb adjustment...you name it. Give it a good "once over", check your wires, cap/rotor, plugs, ensure your carb is tight and clean.

 

[a1nowell]

Re: mercury cruiser 170 hp temp

On my 170/470, I solved alll, alll my hard/hot starting problems when I converted my lawnmower type charging system to a altenator from ww.breezeworks.com. As for my operating temp, around 160. In SE Texas current lake temp 84 degrees.

Larry

 

[stonyloam]

Re: mercury cruiser 170 hp temp

I have a 1987 mercury cruiser 170 hp I/O what is the normail operating temp and rpms for this motor. Also if i dont run the blower motor it doesnt get over 175 in temp .

You should have a160 F thermostat in that motor, and normal operating temperature is 165-200 F, so 175 is not unreasonable. Your impeller should be changed at least every other year to be safe. The temperature you are running should not affect your starting. Almost forgot, for your engine Max WOT 4200-4400 RPM.

 

[southwest395]

Re: mercury cruiser 170 hp temp

ok the temp is good then. cause it doesnt get over 175 degrees. But when i pull the motor cover the engine is hot i cant touch barely. impeller new and heat exchanger been serviced and repaired. the whole back of the boat it closed off . i dont know if its normal for that motor to get hot. also if i run it hard and let it sit for a moment. it will just crank and crank. but it wont start untill i let it sit for about 20 mins. now this motor doesnt have the external altenator, carb was just rrebuilt. is this normal for this motor

 

[stonyloam]

Re: mercury cruiser 170 hp temp

But when i pull the motor cover the engine is hot i cant touch barely.

Well yeah, 175 degrees is HOT!. Remember this is a closed cooling engine, like your car, that gets hot too. You may need to give it a little (or a lot ) of throttle or maybe a pump or two to get it to start. when mine is hot and been sitting for a few minutes, I have to give it about 1/2 throttle to get her started. Play around with it a bit. Good luck.

 

[Scott Danforth]

Re: mercury cruiser 170 hp temp

160F is about the limit that people can handle touching. it is also known as the scalding temperature. so 175 will be too hot to touch.