1995 Johnson 88 hp overheat alarm with new parts.

This is my first post on this site, but I have been lurking here for a few months (solved my cold start problem with carb rebuild and proper procedure!). Anyway, when running in the warm waters of the Florida Intercoastal waterway I get an over temp alarm when running above 4000 rpm?s. I changed the impeller, but it appeared to be in good condition. So then I replaced the thermostats and relief valves.
I took it out this weekend and it had the same problem. I checked the temp of the heads with my hand and I could keep it there for a couple seconds. Both heads felt about the same temperature (very warm, but didn?t seem too hot). Steady stream coming from the pee hole, but the water was cool coming out. It might be slightly warmer than the 75 degree waterway temp. The engine does not slow down when the alarm sounds and it persists for a few minutes while running at idle speed. On muffs, warm water flows from the foot area but cool from the pee hole. Any ideas?

Thanks to all who reply as I have solved many problems by using the search button, but this one has me stumped!

Re: 1995 Johnson 88 hp overheat alarm with new parts.

you are running in salt water, look at the tstats, and poppets. could be corroded and not allowing enough water to pass. you have 2 stats.

Re: 1995 Johnson 88 hp overheat alarm with new parts.

I have replaced both the poppets and tstats