over heating at high RPM

[zinbaad]

Running the twin 315's has been without incident these past two years. This summer while pulling friends in a Tube, running yanmars for minutes 3400-3600 rpms, alarm sounds and starboard engine goes to over heat @ 200 for seconds. . Normal range was 175-180 degrees. Check, antifreeze, ok raw water flowing freely out exhaust. Restarted & kept to 3000-3200 without incident rest of summer. I would notice temp creep up each time I would exceed 3400 rpm but i never usually run that high (jus testing)
After seeing a friends intercooler pulled out, all crusted inside and the multiple tubes that antifreeze runs through (and restricted flow)I had a better Idea of why temps would rise.
After a nice afternoon visit from "Robs" and a cruise to the United Nations & back I decided to take him up on his offer of his plumb setup & pump to run a complete "Rydlyme Flush" which made more sense to me than just cleaning the intercooler. Ordered a 5 gal pail direct Rydlyme ($120) , hooked up fitting (See Robs Post) pumped Rydlyme 1/2 hour each way (simply swith hose on pump, lol)with a 1/2 wait between. With intercooler, tranny coller & oil cooler now flushed temp stays slight below 180" line up to 3400, slightly rises in higher rpms but not issue..
Thanks Rob for all your help

[RobS]

Oh, you had me for a minute there. I was reading this thinking, Oh crap Eddy's still overheating the starboard engine. Glad the flush helped. One thing you can now move from the "do-list" to the "done-list"

I must say my do-list is down to nil. For now anyway...

Here's the link to the thread Eddie is taking about: viewtopic.php?f=7&t=2054&hilit=rydlyme

And thank you for the scenic cruise down the river and even better for letting me run Mahalo most of the trip. I was stopping by Ed's store for a quick hello and he starting talking about the best way to setup the cooling loop flush. So I offered to show him the connection points, etc. right on the engines. I followed him over to the boat. And then he said, if you had the time I'd take you for a cruise down to the U.N. I said well I hope you mean that because it's only 1:00 and I'm meeting a client at the 7:00 Yankee game tonite so let's go!

Thanks again for the ride and the beer, even though it was Bud Light Lime

[zinbaad]

Very welcome Rob...I do hope the Yankees won that night.