125hp overheating

[galillo]

Have a Force 125ho 1989 and is getting hot, I change the impeller and water is running good, the question that I have is that if the frywheel have some dents one is aorund 1.5" and another about 1" trying to pull this out, this can cause the overheating.?

I know the motor is clean inside water conducts because i opened by my self, one more thing i don't have a termostate on it.

Thanks.

 

[galillo]

Re: 125hp overheating

please some body to help me.

 

[paw2000]

Re: 125hp overheating

When you are running the motor, is it in the water or using ear muffs? reason I ask, I have the 125 1988 and the ear muffs don't fit well and even tho water may be coming out its not enough. I now use a tub to run the motor and its much better. You can also loosen the water plug on top of the block near the thermo stat, start the motor and slowly remove the plug, does water come out? you may have internal blockage from salt, or mud bees. water out doesn't mean its circulating, others know more and can be more precise, but i think no thermostat might not allow water to circulate properly.

When I run my motor in the tub, I use a cheapie food thermeter and catch the water in a pan coming from the upper water outlet and its right around 150 degrees, this is how I check my motor, not high tech but it works.

 

[galillo]

Re: 125hp overheating

Hi

This happen to me when i'm on the open ocean running and the temperature of the water on the sea is around 80,s.

I know the termostate is really good in cool water but I don't really no if the water is around 80's and 90's will really help.

 

[pnwboat]

Re: 125hp overheating

I'm not quite sure what you mean by dents in the flywheel? Do you have a picture? I can't think of any reason a damaged flywheel would cause the motor to overheat. If the keyway in the hole in the middle of the flywheel was damaged, it would change the timing, but I doubt that the motor would run at all.

Even with the water temperature around 80 degree (Fahrenheit I assume, not Celcius) with a thermostat, it should not over heat. Is the alarm going off?

If it is, you should probably start by checking the compression in each cylinder. A bad head gasket could possibly cause your problem.

 

[john from md]

Re: 125hp overheating

+1 on pnwboats suggestion on the compression test.

How do you know the engine is overheating? Is the buzzer going off? What speed/rpm does this occur? What kind of boat is it on, what is your WOT speed and rpm?

John

 

[steelheadbob]

Re: 125hp overheating

we had a 1979 125 chrysler on our renkin for two months.... It kept over heating in low idle and past 3/4 throt.... Kept blowing gaskets!!!!!! WQe took it in 5 times, had the impeller replaced twice, 5 gaskets, had the alum head rebuilt and shaved and about a 1,000 bucks later it still over heated... One day we were on portage lakes running half throttle, over heat alarm went off and heard alound clank and came to a stop!!!! Here the whole time,,,,,, and alot of people miss this,,,, 8 out of the 20 reed valves behind the carbs were stuck wide open! My brother in law took the whole block to his work, took it apart,,, and all four piston arms were warped.... So the story is,,,, CHECK THE REED VALVES AND MAKE SURE WHEN CLOSED, U SEE NO DAY LIGHT THROUGH THEM!!!!!!!!

 

[galillo]

Re: 125hp overheating

usually this happen at 25 or 30 miles on open sea then i have to wait until with the motor off until the alarm is off , somettimes happen sometimes not, the dents on the fry weel that i have is becouse i try to pull it off with the wrong tool so I broke some dents on it.

my boat is abeyliner 1989 19.5' cabin with 125hp serial 125IX8C, the compresion is about 115 in all cylinders.

 

[john from md]

Re: 125hp overheating

I suspect that you have build up in your cooling system. I suggest that you pull the head off and clean the passages.

If these engines are used in salt water and they are not flushed routinely, you get a build up of salt throughout the cooling passages. You will need to replace the head gasket when you do this and it will also be a good time to inspect the condition of your pistons and cylinders.

It is also possible that your relief valve is bypassing water. I hope this is not the case because trying to get them out is a ***** and you always break off bolts.

John

 

[galillo]

Re: 125hp overheating

Thanks this motor don't have a relief valve is only a hole.! i been asking here before if shut have this motor that valve but someone tell me that this model do not use a relief valve.

 

[john from md]

Re: 125hp overheating

Hmm, that's news to me. Look at the forward bottom corner of your exhaust plate on the side of the engine. If there is a cover being held in with two bolts, that is your over pressure relief valve.

John

 

[galillo]

Re: 125hp overheating

I do check for the relief valve and is only a hole in there so most of the water go under that hole and a little bit to the rest of the motor and head.