1988 force 50 HP cooling or water pump question.

goodtimesfishing

Petty Officer 3rd Class
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Jan 8, 2011
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I have a 50 HP force (1988) that I put new impeller and installed telltale in last year. Telltale has worked great with a solid stream of water. Took boat out and it ran great all day(about 8 gallons of running time). On my way in got in some eel grass and plugged intake causing a hissing steam sound out telltale. Without turning motor off I tilted motor up removed grass(took 2 seconds if that) and was on my way. However even though I cleared intake I no longer get a solid stream of water out telltale I installed.....seems like excess air pressure coming out telltale and more of a spitting then a stream. Motor starts right up in barrel and stays cool but what is causing all the air to come out pee hole (I know air comes out factory telltale but telltale I installed was always a steady stream of water). Any suggestions or info appreciated.
 

Jiggz

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Oct 23, 2009
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Re: 1988 force 50 HP cooling or water pump question.

Need to open the t-stat cover and check for blockage on the t-stat itself. If you do not find any, then it is time to remove the lower unit and back flush the cooling system from the t-stat port. Do an inspection of the impeller too and back flush as required.
 

goodtimesfishing

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Re: 1988 force 50 HP cooling or water pump question.

Thanks jiggz.....I am worried about if the extra air pressure could be coming from a leaking head gasket.....but it runs??? I just can't figure out where the extra air pressure is coming from. If I would not of installed new telltale I would not even know there was a problem. I have never seen that much air out the telltale. I would figure water pump problem if it was just a weak stream but the excess air concerns me.
 

Jiggz

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Re: 1988 force 50 HP cooling or water pump question.

I'm not sure if what you see is air or steam. Since the motor is running fine, I would surmised it is steam and is caused by a highly reduced water flow in the cylinders. However, if it is air it is probably, you have a faulty head gasket. You should be able to tell if this is air or steam by closely watching the tell tale as soon as you start the motor from a cold status. Since the block is still cold there should be no steam coming out of the telltale, but if there is "air" then it tells you will need to check the head gasket. You need to correct the problem as soon as you can before it gets worse. However, if no "air" comes out during initial start from a cold engine, it tells me it is steam created from the reduced flow of water into the cylinder water ports. Remember, cooling water only goes through the cylinder ports after the t-stat opens which happens only after the engine warms up.
 

goodtimesfishing

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Re: 1988 force 50 HP cooling or water pump question.

Jiggz .....what you said makes total sense and leads me to believe it is time for new head gasket. Even when I first start it cold it blows air...just surprised at how easy it starts, and runs, if head gasket is leaking.
Any other thoughts or comments appreciated.
 

goodtimesfishing

Petty Officer 3rd Class
Joined
Jan 8, 2011
Messages
84
Re: 1988 force 50 HP cooling or water pump question.

I pulled the lower end and impeller is still like new. Pulled head and see 3 spots it was leaking. Oh ya did compression test first and got 90 on lower and 110 in upper.
Going to get gasket now....anyone know torque and sequence?????
 

Jiggz

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3,817
Re: 1988 force 50 HP cooling or water pump question.

Torque sequence should be spiral sequence as shown below at 270 inch-lb (22.5 FT-LBS). The pic below is for 125HP but the sequence is the same. Make sure you do at least 2 or 3 step torquing, i.e. torque all bolts first with 90 in-lb and then start all over with 180 and then 270 in-lb. Finally, starting from the beginning double check all torque and make sure none of the bolts will turn more than 1/8 of a turn. If any bolt turns more than 1/8 of a turn, you need to re-torque all bolts again. After you ran the engine to operating temp for at least an hour, check your torque settings again when engine is cold.

Torgue sequence 125 HP.jpg
 

Jiggz

Captain
Joined
Oct 23, 2009
Messages
3,817
Re: 1988 force 50 HP cooling or water pump question.

Jiggz .....what you said makes total sense and leads me to believe it is time for new head gasket. Even when I first start it cold it blows air...just surprised at how easy it starts, and runs, if head gasket is leaking.
Any other thoughts or comments appreciated.

You obviously had on overheating casualty caused by the clogged water inlet. Lucky for you it was only the gasket that was damaged, on some it can result in catastrophic damage like broken rings or scorn cylinder.
 
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