My 1971 38 commander is overheating it will cool down with more throttle but now that isn’t cooling enough it doesn’t show more than 225 on the temperature???? This is a new one for me!!?????
Possible causes of overheating at low rpm would be a bad water pump impeller, slipping water pump belt, or air getting in the supply side from a leaky sea water strainer, loose hose connection, or leak in supply hose. Start with easy things first like checking hose clamps, belt tension, and checking impeller.
I could blow through the intake and it went through I took off the 4 bolt cover where 2 hoses go to the exhaust manifolds I saw a spring horizontal something in there very little water coming up from it when I started the motor with the 4 bolt hoses are hooked to
There are 2 water pumps, engine circulating pump (metal impeller), mounted on front center (center pulley) of engine and sea water pump pulley to right or left of center pulley, typically one side is alternator other side sea water pump, this will have a rubber impeller. Impeller is probably bad or bronze housing worn.
Captain Robert ...I hope you also replaced the brass cam wear plate inside the pump housing . That part is Sherwood # 10944 and must be replaced when an impellor is replaced .
@tim toth are you saying you HAVE to replace the cam every time you change an impeller? That's a bit excessive in my book but a good inspection is warranted.
Captain Lee .....The only way to check a brass cam wear plate is with a caliper after cam wear plate is removed from pump housing .. When new the Sherwood spec is .196 thickness measured at the center radius . A visual inspection will never be correct service maintenance . As the cam plate wears thinner pumping performance is reduced per Sherwood instructions . Just think how many impellor pumps in all marinas across the country are in use with decades old brass cam wear plates !
Oh 427 ford Chris craft
Raw water cooled or fresh water?
Raw water
Possible causes of overheating at low rpm would be a bad water pump impeller, slipping water pump belt, or air getting in the supply side from a leaky sea water strainer, loose hose connection, or leak in supply hose. Start with easy things first like checking hose clamps, belt tension, and checking impeller.
Yes fresh
I could blow through the intake and it went through I took off the 4 bolt cover where 2 hoses go to the exhaust manifolds I saw a spring horizontal something in there very little water coming up from it when I started the motor with the 4 bolt hoses are hooked to
Thank you I started with the easy stuff first but my impeller is metal
Thank you for your help I really appreciate it!!! Love this club!!
There are 2 water pumps, engine circulating pump (metal impeller), mounted on front center (center pulley) of engine and sea water pump pulley to right or left of center pulley, typically one side is alternator other side sea water pump, this will have a rubber impeller. Impeller is probably bad or bronze housing worn.
Thank you!! I already have it out and 2 new ones on the way overnight. Always learning!!
Maybee one more season out of it lol!
Captain Robert ...I hope you also replaced the brass cam wear plate inside the pump housing . That part is Sherwood # 10944 and must be replaced when an impellor is replaced .
Tim
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@tim toth are you saying you HAVE to replace the cam every time you change an impeller? That's a bit excessive in my book but a good inspection is warranted.
Captain Lee .....The only way to check a brass cam wear plate is with a caliper after cam wear plate is removed from pump housing .. When new the Sherwood spec is .196 thickness measured at the center radius . A visual inspection will never be correct service maintenance . As the cam plate wears thinner pumping performance is reduced per Sherwood instructions . Just think how many impellor pumps in all marinas across the country are in use with decades old brass cam wear plates !
Tim
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No just the impeller it’s just the first time changing it on the 1971 38 commander!!