Hello,
I have a 1981 silverton 31c with twin 318's I recently refit the entire boat, and went to a single helm station in the salon. Since putting it back in the water, I get very high temp indications on both motors. I did replace the sending units with single station senders. I replaced the exhaust elbows last year, and had the heat exchangers cleaned out while it was being refit. both raw water pumps were rebuilt, with new bearings and impellers.I get good raw water flow. The indications I get are around 210 to 220F, but when I shoot the coolant inlet of the heat exchanger with an IR thermometer, it reads about 141, and the exit reads about 129. the manifolds are cool enough to touch with your hand. the coolant reservoir also reads about 140-142. Since it doesn't actually overheat (steam, blown hoses, etc), I have to assume my indications are way off. they do climb to those temps quite quickly. The only theory I have now is that I did not remove the wiring harness that actually went up to the flybridge. I just coiled it up and left it in the engine compartment, tied down. It looked too complicated to extricate from the rest of the wiring, and since everthing worked, I figured I'd leave it. Since the Dual station/single station difference on senders has to do with the additional resistance on the other gauge, is it possible that the fact that the additional wiring is still in place could have and adverse effect on the readings I'm getting at the helm?
I have a 1981 silverton 31c with twin 318's I recently refit the entire boat, and went to a single helm station in the salon. Since putting it back in the water, I get very high temp indications on both motors. I did replace the sending units with single station senders. I replaced the exhaust elbows last year, and had the heat exchangers cleaned out while it was being refit. both raw water pumps were rebuilt, with new bearings and impellers.I get good raw water flow. The indications I get are around 210 to 220F, but when I shoot the coolant inlet of the heat exchanger with an IR thermometer, it reads about 141, and the exit reads about 129. the manifolds are cool enough to touch with your hand. the coolant reservoir also reads about 140-142. Since it doesn't actually overheat (steam, blown hoses, etc), I have to assume my indications are way off. they do climb to those temps quite quickly. The only theory I have now is that I did not remove the wiring harness that actually went up to the flybridge. I just coiled it up and left it in the engine compartment, tied down. It looked too complicated to extricate from the rest of the wiring, and since everthing worked, I figured I'd leave it. Since the Dual station/single station difference on senders has to do with the additional resistance on the other gauge, is it possible that the fact that the additional wiring is still in place could have and adverse effect on the readings I'm getting at the helm?