When do you replace T stats? '03 Merc 225 EFI OT651558

[digthemup]

I have not replaced my T stats on this motor in the last 5 yrs, however, I do take them out for cleaning/inspection periodically.
I do not fish much skinny water or swampy area, and most of my hours are in the St Lawrence river gin clear rocky bays.

Is there any schedule time limit for replacing them? since unlike I/O T stats, they are pretty pricey for a set, and by the grace of Christ no issues with current 1's

Thank you in advance to y'all.

[Bob G.]

I’ve never taken my thermostats out on the motor in my signature. I would only take them out if there was a problem.

[lpugh]

I have never has to replace a Mercury outboard stat, cleaned and tested them many times

[digthemup]

I have never has to replace a Mercury outboard stat, cleaned and tested them many times

Leon,
That is what I do with them, and I put a new gasket every time on reinstall. They seem to test out well, but I thought that perhaps there was an hour limit to them.
Thank you

[EuropeanAM]

As long as they function properly, and are not corroded, there is not a mandatory replacement in place on THESE engines. Thermostat functional testing/inspection should be part of your ANNUAL Maintenance (once every 364.99 days, or 100 hours of operation, whichever happens FIRST). Applies to ALL 3L 2-stroke product.

[digthemup]

Thanks Don for letting me know that there is no mandatory replacement. They look and function correctly, so just a new gasket and back into place.