79 35hp head temps high, lots of water

[relicshunter]

It a 35el79a and has a new pump, changed the lower oil, rebuilt started, rebuilt carb, new plugs, rewired it. I have no history on it, but so far it starts like a dream and a strong stream out the tell tale. I am at the adjusting stage and I am a little baffled by the temp readings I get on the thermostat cover and side of the head. The water out of the tell tale and exhaust ports is heavy and what I would call tepid, but the temp reading off the thermo cover climbs over 162 (which I thought is the high range). When it got to 179 I shut it down. Meanwhile the readings on the left side of the cylinder head are over 210 for the upper one and only 145 for the lower one. The exhaust water does not start instantly when cold, so I am thinking there is a functioning thermostat in there, but I am not sure. Looks like maybe areas could be clogged in the water passages, making the top run hotter. It seams unlikely though since the water temps are just a nice hand washing temp. ??

[Solarman]

Sounds like you should get a large enough plastic container, trash can, and run 4-6 gals of vinegar (or another corrosion flush - salt away?), add enough water to cover the water pump, and run in this solution for as long as able (1-2 good hours run time). If solution gets too hot, shut it down and let it cool. Repeat the run after solution cools down enough. After you have run the solution through the motor for 1.5 hours, check to see if temps between cylinders have balanced out.

Prior to flushing, you should check that your thermostats are not the problem. If they are not opening fully, they may not be allowing enough water to flow through all the pas-sages.

If this flushing doesn't help, you may have to open the water pas-sages and clean manually?

Good luck. Let us know how it's going.

[relicshunter]

I have flushed some vinegar through it, can't run it very long each time. My understanding is that water will not come out the exhaust ports until the thermostat opens. This is looking at the water trail chart in the book. It seems that it opens reliably. I will give it a few more flushes, but I think I am looking at pulling the covers and taking a look. I just hate broken bolts. It looks like they have been undone at sometime since there is missing paint and circular scraps around some bolts. It's a freshwater motor. It would be nice to gain some compression but replacing that gasket also.