Yamaha 250SX TXRY Overheat Problem

[VANGRADY]

I had my mechanic come down and do a dockside test with his Thermometer to check out my low idle overheat issue on both engines. Of course when he was there it did not happen. His theory is that since we had a very cold winter, the wax in the T Stats might have hardened and it might have taken one or two times of starting and running the engines to loosen up the T Stats. Does this make sense to owners who keep their boats in cold climates? We started up the engines and after about 8 minutes, the top cylinders reached 150 deg and then quickly dropped down to 106 deg after the T Stat opened. Both engines ran at this temperature for about 40 minutes without an issue. The T Stats are one year old. The mechanic also took apart the PRV's and they were both clean. I still do not know if I have a problem that is intermittant or if it is solved??

[Tucker]

Northern Maryland here. Never heard of that problem. Never new stats had wax in them. I'd replace both stats & gaskets to be safe. Beats a tow. Buy a shop manual and get to know the guys on this web site. You'll be able to do most if not all your own maintenance and you won't need a wax mechanic. Boats.net also has good prices and delivery on parts.