Force 125 still overheating???

[WILL23]

The alarm on my 87 Force 125 goes off after 5-10 minutes on the water. After a good decarb I have good compression and I just replaced the impeller, water pump housing and the thermoswitch. There does not seem to be any blockage in the water ports. Does anyone have any suggestions why this is happening?

 

[The Marine Doctor]

Re: Force 125 still overheating???

Are you sure that when you put the gearcase back up into place that you aligned the watertube?<br /><br />TMD

 

[WILL23]

Re: Force 125 still overheating???

Yes it is aligned. The water flow is very steady.

 

[The Marine Doctor]

Re: Force 125 still overheating???

What are the compression values?<br /><br />TMD

 

[WILL23]

Re: Force 125 still overheating???

Last checked #1-126 #2-131 #3-121 #4-96

 

[The Marine Doctor]

Re: Force 125 still overheating???

You have a blown head gasket on #4 cyl.<br /><br />Remove the head and plain it need be...and replace the head gasket.<br /><br />TMD

 

[WILL23]

Re: Force 125 still overheating???

When the head gasket is blown shouldn't there be water behind the spark plug?

 

[The Marine Doctor]

Re: Force 125 still overheating???

Nope. If the compression was lower yes.<br /><br />Trust me on this one.<br /><br />TMD

 

[WILL23]

Re: Force 125 still overheating???

TMD - I replaced the head gasket(it was blown) and now have 130+ on all cylinders. Still the the alarm sounded after about 5 minutes running at WOT.

 

[The Marine Doctor]

Re: Force 125 still overheating???

Is there water comming out the discharge holes on the back of the leg?<br /><br />TMD

 

[WILL23]

Re: Force 125 still overheating???

Yes, there is a steady spray from the two discharge holes and a steady stream from the exhaust port. I removed the thermostat housing and ran it with it off and there is lot of water pumping through.

 

[revertmastec]

Re: Force 125 still overheating???

Are we sure there is not a bad ground or defective horn. Is the motor actualy getting hot?<br />Next time the horn sounds try putting your hand on the head. You should be able to leave it there for a few sconds without being burned.

 

[WILL23]

Re: Force 125 still overheating???

I have put my hand on the head when the alarm sounds. It is hot but not hot enough to burn me right away. How do check for a defective horn?

 

[The Marine Doctor]

Re: Force 125 still overheating???

Do the sizzle check...if you put water on the head when it overheats...does it sizzle and boil.<br /><br />Does it overheat when the TStat is not in?<br /><br />TMD

 

[WILL23]

Re: Force 125 still overheating???

I do not run it with a thermostat. It does not sizzle or boil when I put water on it.

 

[The Marine Doctor]

Re: Force 125 still overheating???

Would you be able to run it without the Tstat...for a short time?<br /><br />See if it still overheats.<br /><br />If it does not over heat..you will have found your problem.<br /><br />TMD

 

[kwk]

Re: Force 125 still overheating???

I've been having a similar problem with my 125 HP. Replaced everything like you, including the T-stat. I pulled off the exhaust port plate cover and found some old water impeller debris floating around waiting to cause trouble and one big piece wedged into the water passage. The passages are pretty small in some places and a big enough chunk at the wrong location could really restrict the flow. Unfortunately, I don't know if I fixed my problem because in the process of checking the cylinder head passages, I found a beat up piston on cylinder #4. Now my problems are much bigger than overheating.