What is up with the Universal 25?!? New impellers, flushed fresh water, replaced thermostat and changed oil. This thing overheats at 5.5 knts!! Any thoughts? Fairwinds, Jaydog
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B
Bob
Check inlet strainer
Hi Jaydog, Check the inlet strainer and water flow to pump. Can run without thermostat to eliminate that item. Good luck
Hi Jaydog, Check the inlet strainer and water flow to pump. Can run without thermostat to eliminate that item. Good luck
C
Chuck R
Some ideas for you to check.
When dealing with over heating here are some ideas. 1 Thermostat ( put in a pan of boiling water to make sure it opens. New one can stick) 2 New impeller needs to be the exact right size. ( Bought a Shurwood impeller for their pump and they gave me one that was one size to small caused a weak flow as engine speed increased. 3 Since from the pump to the strainer to the sea cock is all a suction hose make sure the hoses are in good condition, They should have a wire coiled to keep from collapsing under suction, ( many times I have seen where the rubber inside comes apart and acts like a valve and shuts or slows water flow. 4 Lets hope it is not this one. If when removing the old impeller there was bits and pieces missing this is not good. Little chunks of rubber get in the the water passages in the engine and can clog and slow flow of water. 5. An expensive but doable repair and some engines are prone to Leakey head gaskets or even a cracked head,. I t is just a good idea to change out that rubber impeller about every two years whether it needs it or not. The little vanes on the impeller are extremely bent even when the engine is not running. As they age then loose their memory and want to stay bent. Very cheap insurance. Usually not difficult to change out. Good Luck. Hope you find the problem with little grief
When dealing with over heating here are some ideas. 1 Thermostat ( put in a pan of boiling water to make sure it opens. New one can stick) 2 New impeller needs to be the exact right size. ( Bought a Shurwood impeller for their pump and they gave me one that was one size to small caused a weak flow as engine speed increased. 3 Since from the pump to the strainer to the sea cock is all a suction hose make sure the hoses are in good condition, They should have a wire coiled to keep from collapsing under suction, ( many times I have seen where the rubber inside comes apart and acts like a valve and shuts or slows water flow. 4 Lets hope it is not this one. If when removing the old impeller there was bits and pieces missing this is not good. Little chunks of rubber get in the the water passages in the engine and can clog and slow flow of water. 5. An expensive but doable repair and some engines are prone to Leakey head gaskets or even a cracked head,. I t is just a good idea to change out that rubber impeller about every two years whether it needs it or not. The little vanes on the impeller are extremely bent even when the engine is not running. As they age then loose their memory and want to stay bent. Very cheap insurance. Usually not difficult to change out. Good Luck. Hope you find the problem with little grief
J
jason wiggins
Thanx Chuck and Bob
I have replaced the impellers there are two, one for the raw water and another for the engin, checked the thermostat. I do have a water heater in the loop, but I can't see that causing an overheat....The water inlet is good,I get good flow out the exhaust. Also I've noticed it only overheats when the prop is in gear?!?!?!? Jaydog
I have replaced the impellers there are two, one for the raw water and another for the engin, checked the thermostat. I do have a water heater in the loop, but I can't see that causing an overheat....The water inlet is good,I get good flow out the exhaust. Also I've noticed it only overheats when the prop is in gear?!?!?!? Jaydog
C
Chuck R
Transmission cooler
Jaydog, I'm not familiar with these small engines. Larger powerboat engines have coolers for the transmission oil on the intake. When you put your motor in gear it puts a load on making the engine work creating more friction and a demand for more cooling. Is there a way you could hook up a temporary direct intake line to the raw water pump. A lot of boats have a shut off valve at the through hull fitting. This way you could eliminate the strainer, heater and trans cooler. Also is your engine a closed cooling system with anti freeze?
Jaydog, I'm not familiar with these small engines. Larger powerboat engines have coolers for the transmission oil on the intake. When you put your motor in gear it puts a load on making the engine work creating more friction and a demand for more cooling. Is there a way you could hook up a temporary direct intake line to the raw water pump. A lot of boats have a shut off valve at the through hull fitting. This way you could eliminate the strainer, heater and trans cooler. Also is your engine a closed cooling system with anti freeze?
Water heater
Jaydog - Is the water heater a new addition to the boat ? If so, were you experiencing any overheat problems before it was added ? Depending on the plumbing layout, the water heater could be causing a reduced coolant flow thru the engine. You have to make sure that there isn't air trapped anywhere in the FWC loop by bleeding it. Maybe, take the water heater out of the loop , make sure the engine is full of coolant with no air pockets and see if the overheating persists. Presumably you've checked for a line/rope wrapped around the shaft and that your stuffing box isn't too tight and the transmission has enuf lube in it ??
Jaydog - Is the water heater a new addition to the boat ? If so, were you experiencing any overheat problems before it was added ? Depending on the plumbing layout, the water heater could be causing a reduced coolant flow thru the engine. You have to make sure that there isn't air trapped anywhere in the FWC loop by bleeding it. Maybe, take the water heater out of the loop , make sure the engine is full of coolant with no air pockets and see if the overheating persists. Presumably you've checked for a line/rope wrapped around the shaft and that your stuffing box isn't too tight and the transmission has enuf lube in it ??
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