stb eng over heats over 3200 rpms. running big offshore pick ups big kpm strainers that are clean, running 20lbs water pressure, fresh rebuilt raw water pumps, crossovers, no thermastat, flowing water out the exhaust but when i lean on it temp climbs right up, but it always runs 20 degrees hotter than its twin brother. yanked off the water pump before i went out today everything seems perfect impeller is in great shape. any suggestions? thx ratman

Hi ratman,
you didnt mention what motors you have so this is kind of shooting in the dark.... when you had the pump apart where there any scores high rpm overheat alot of times is cavitation in the pump caused by scores

goodt, 577 n/a's 9.4 to 1 comp. the pump was rebuilt and appears to be in great shape. i will take it apart inspect it a little better and replace the impeller.

Have you had an impellar go bad in that engine? Any chance of a broke off vane plugging something?

no, fresh motors, all new hoses, raw water pick ups, freshly rebuilt water pumps,

ttt

Have you tried switching sending units or gauges? Is oil temp the same on both?

its getting hot the problem is not with the gauge or sender. my oil temp gauges are not wired properly and are not reading, i am having the oil temp gauges rewired this week.

ttt, any ideas folks? lil help here, thx

Brand new engines, but are the oil coolers new? Also any air leaks on the suction side of the raw water pickup with reduce flow.

BT