Exhaust temp problem.

[Bill Root]

Unfortunately the mechanic who was supposed to help me do this job before we left Marsh Harbor stood me up. We came back all the way to West Palm Beach at 9.5K. That's not a prob lem for us, but it would have been nice to have the extra speed if we had needed to outrun a storm. Fortunately the weather was close to perfect. We're headed to Titusville now where we'll keep the boat for awhile. My son's coming down from Atlanta next week to give me a hand. We'll remove and clean everything in the raw water supply on that engine, then take it out for sea trial. I'll let you know how we make out.

 

[Bill Root]

My son came down from Atlanta this past weekend to give me a hand pulling the heat exchangers and spray ring. (Torn rotator cuff gives me only 50% use of left arm. Surgery to fix next week. Ugh!)
We found the problem. Spray ring was clear, but the stabilizer heat exchanger that is in that exhaust water line ahead of the spray ring had a large piece of the zinc that is on the inlet side broken off. Apparently when the engine speed was increased past about 1250 rpm that piece would be pushed up against the intermediate baffle and block about half the water flow through the exchanger. We removed the broken piece and boiled out the exchanger. Replaced it and the engine now runs 180 degrees at 2350 cruise, no exhaust temp alarm. The temp at the exhaust temp sending unit reads 110 degrees after 20 minutes at cruise. Thanks to everyone for their insights.