Overheating Force 125- maybe this was the problem?

[Justinde]

HI All

I have replaced the water pump with a new unit. Great success. I bought a second hand exhaust plate from ebay, and some gaskets. Attached are some pictures of the inside of the old plate. Looks like the old owner has run aground somewhere and it was full of sand. Not only that, most of the water jackets were corroded and calcified rock hard, ensuring no water flow. Do you think this contributed to the overheating issue?:facepalm:

p.s. I only broke 1 head off a bolt. The other came off with a little persuasion and some WD40..... One bolt needs drilling out. I think, from reading the posts here, that I am VERY fortunate!

 

[jerryjerry05]

Re: Overheating Force 125- maybe this was the problem?

Looks like no one ever flushed the motor.Salt water can be rough.J

 

[Idaho gt150]

Re: Overheating Force 125- maybe this was the problem?

last summer i spent the month of august drilling out broken bolts. 10 broken bolts on the last one i snapped the drill bit off in the middle of bolt. just sayin i feel your pain.

 

[Justinde]

Re: Overheating Force 125- maybe this was the problem?

Thanks Idaho...... I snapped the 1.... and it hurts bad. 10....... Now I am feeling your pain!!

I am SO lucky to have snapped the 1 only. `Doesn't the old plate look like sh*t! As Jerry said, must not have been flushed- ever. This MUST have been the cause of the overheat warning. Idle- great, low revs, great, higher RPM- oh bugger I'm overheating! This plate was SO calcified, the pic's do not do it justice.

Cheers

 

[NYBo]

Re: Overheating Force 125- maybe this was the problem?

Nah, I'm sure the crud and the overheating had nothing to do with each other. Purely coincidental!

Just a tip for the next time you need to tear into the motor: WD-40 isn't a very good penetrating oil. Over here, we use PB Blaster, Kroil, Liquid Wrench, or the like. Not sue what's available in your part of the world. A homemade mix of half automatic transmission fluid and half acetone is supposed to work as well as or better than the commercial products.

 

[Justinde]

Re: Overheating Force 125- maybe this was the problem?

Once I have the waterpump back on, should I put the exhaust plate on without the gaskets, run the engine on fresh water ( on the hose) for 10-15 minutes, then remove the exhaust plate again and inspect for more sand/silt- or do the gaskets stop that stuff getting into the pistons? Should I just remove the head anyways and check the watervanes as suggested? HAving been rebuilt 10 hours ago, my guess is that the calcification is from years of neglect, but the sand ( which was loose) was probably done after the rebuild, and recently, probably from running aground. Would there still be silt/sand in the watervanes, and if it is, would the new waterpump and new exhaust plate allow this sand free passage out?

 

[pnwboat]

Re: Overheating Force 125- maybe this was the problem?

Running it without gaskets on the exhaust plate is probably not a good idea. Water leak on the exhaust plate can get blown into the cylinders through the exhaust ports. Especially the lower cylinders. There is one other water passage that I would be concerned with that is part of the head itself if you haven't already checked it out for corrosion. Item 79 in the diagram below. The "head cover" forms a water passage through the head. Unfortunately you have to remove the head to take it off. There is no gasket to seal the head cover, just high temp. silicone sealant. Once you remove the head, it's held in place with three bolts located by the spark plug holes.

http://www.boats.net/parts/search/Merc2/Force/125%20H.P.%20%281989%29/1253X9B/POWER%20HEAD/parts.html