What temp does your 4JH3 run

[callistov42]

I have a 50 hp normally aspirated 4Jh3 that has run at 180° for years. Recently it has gone up just 5° to 185°. I have owned the boat for 30 years and this engine is 14 years old and it is a little concerning, especially because I am about to bring it across the Gulf back to Texas from Nassau.
It holds at 185° for long multi day runs at 1800 rpm and doesn't seem to be increasing from there. What temp does your 4JH3 run at?

[Garrettw]

I have a 4Jh5. It runs at the cycling temp of the thermostat (170F I think), but can vary a small amount with the raw water temp. Have you checked your thermostat for proper function?

Different topic: will you do a straight run from the Keys to TX?

[callistov42]

Yes, straight across. I'm thinking 7-8 days.

[Garrettw]

Have a safe trip! Hopefully Beryl doesn’t kick up the sea state too much for you in the eastern gulf.

[Renegde_Sailor]

My 4JH3E runs right at about 180, how long has it been since you cleaned your strainer and changed your impeller?

[crosswire]

I have a 24 year old 4JH3E with 3000 hours, driving a 20,000 pound, 42 foot modified full keel sailboat with a three bladed prop. I usually run at 1800-2000 rpm and get about 5 knots. The engine temp varies from 165 to 180 depending, apparently, on the surface water temperature. At present, Galveston Bay is near 90 degrees and the engine temp is a steady 180. When the bay cools during the winter, the engine temp goes down to 165 to 170. The engine temp was a steady 180 during a recent 7 hour trip at 2500 rpm into 15 to 18 knot head winds, making 4.5 knots motor sailing (I got tired of tacking the boat; the Houston ship channel is narrow and full of commercial traffic).