Cure one thing and it is always something else. After discovering there was no flow thru the mixing elbow (overheat problem), I replaced same. Sounds easy. Not something you want to try every day. After getting some decent water flow, I discovered that the temp never seemed to go above 140 F. That seemed awful low for an engine, so I put in a new thermostat. The old one was stuck open. It still runs in the 140 F range. Can anyone comment/ help here? Is that the correct operating temp for a YSM12R?
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That's about it Butch!
Butch: That is about it for a raw water cooled Yanmar. This is why they do not have a hot water exchanger for the water heater. There is not enough heat to heat the water. The newer engines have a fresh water recirculating system that does get VERY warm.
Butch: That is about it for a raw water cooled Yanmar. This is why they do not have a hot water exchanger for the water heater. There is not enough heat to heat the water. The newer engines have a fresh water recirculating system that does get VERY warm.
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Mark Smith
Same Thing with my boat.......
I allso replaced my elbow (ugly job) but it stopped the overheating problem! But I allso wondered if my temp was too low. Turns out it not. Don't be afraid to run the motor, it should be ok!
I allso replaced my elbow (ugly job) but it stopped the overheating problem! But I allso wondered if my temp was too low. Turns out it not. Don't be afraid to run the motor, it should be ok!
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Henry Weber
Yanmar engine temp
Butch -- I have a YSB12 also. The engine runs cold. The thermostat is stamped with a number that is the temp in Celsius. I believe it is around 120F.This is Yanmar's design and done for the purpose of reducing saltwater deposits which build up around the water jacket and elbow. It seems that they determined engine coking was not as bad as the salt water problem. Nevertheless when I rebuilt my engine last year I found that the cylinder sleeve was corroded through from the outside about 75% of its thickness. You can't see it until you extract the sleeve from the cylinder. The engine had about 1200hrs and was 23yrs old. Regards, Henry Weber
Butch -- I have a YSB12 also. The engine runs cold. The thermostat is stamped with a number that is the temp in Celsius. I believe it is around 120F.This is Yanmar's design and done for the purpose of reducing saltwater deposits which build up around the water jacket and elbow. It seems that they determined engine coking was not as bad as the salt water problem. Nevertheless when I rebuilt my engine last year I found that the cylinder sleeve was corroded through from the outside about 75% of its thickness. You can't see it until you extract the sleeve from the cylinder. The engine had about 1200hrs and was 23yrs old. Regards, Henry Weber
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Garry Elmer
Freshwater cooling
We have a freshwater kit on our 2QM16 in our 1980 33. It was installed by the previous owner. I believe the kit changed out the thermostat and it's set at 150. Also on our engine the last owner plumbed the hotwater heater before the heat exchanger. We've GOT some hot water when we are motoring! Garry http://www.99main.com/~elmergw/
We have a freshwater kit on our 2QM16 in our 1980 33. It was installed by the previous owner. I believe the kit changed out the thermostat and it's set at 150. Also on our engine the last owner plumbed the hotwater heater before the heat exchanger. We've GOT some hot water when we are motoring! Garry http://www.99main.com/~elmergw/
Garry, FYI
Garry: The reason they use the 140 degree thermostat was to keep the salt water deposits from building up inside the block and plumbing. So the reason you are getting any warm water is in exchange for a overheating problem within your engine. If you want to keep the engine with this thermostat, you may want to consider a flush with Marsolve each year to flush the deposits out of your block. (not a bad idea anyway)
Garry: The reason they use the 140 degree thermostat was to keep the salt water deposits from building up inside the block and plumbing. So the reason you are getting any warm water is in exchange for a overheating problem within your engine. If you want to keep the engine with this thermostat, you may want to consider a flush with Marsolve each year to flush the deposits out of your block. (not a bad idea anyway)
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Garry Elmer
Antifreeze circulates through the engine
With a freshwater/seawater heat exchanger the engine and hot water heater have a closed loop filled with antifreeze. No salt, it can run warmer. I check the seawater side of the heat exchanger and flush as necessary. After loosing the seawater pump I limped almost all the way back to the marina by periodically running the hot water and using the hot water heater as a heat exchanger. Everything worked fine until I ran out of fresh water and had to anchor and put a new impellor into the seawater pump. Gee, for some reason I had to replace all of my exhaust hose after haul out though. GRIN
With a freshwater/seawater heat exchanger the engine and hot water heater have a closed loop filled with antifreeze. No salt, it can run warmer. I check the seawater side of the heat exchanger and flush as necessary. After loosing the seawater pump I limped almost all the way back to the marina by periodically running the hot water and using the hot water heater as a heat exchanger. Everything worked fine until I ran out of fresh water and had to anchor and put a new impellor into the seawater pump. Gee, for some reason I had to replace all of my exhaust hose after haul out though. GRIN
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Butch
Mine has a kit too
Gary, Mine had a kit installed prior to my purchase. Same plumbing to hot water. 150 to 180 sounds like a more reasonable temp for the engine. Now I must locate a higher temp thermostat. Thanks for the reply.
Gary, Mine had a kit installed prior to my purchase. Same plumbing to hot water. 150 to 180 sounds like a more reasonable temp for the engine. Now I must locate a higher temp thermostat. Thanks for the reply.
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Bob
Corrosion through cylinder sleeve or water jacket?
Attent: Henry Webber Your comment sent shivers up my spine and out through my wallet .. when you say "Nevertheless when I rebuilt my engine last year I found that the cylinder sleeve was corroded through from the outside about 75% of its thickness. You can't see it until you extract the sleeve from the cylinder. The engine had about 1200hrs and was 23yrs old." I hope this is what is likely the 'steel sleeve' used for the piston, and not the cast iron sleeve into which the liner fits ?? I'm having my SB8 rebuilt, and I would describe it like you did yours! Any other words you can add. Send off line if preferred: we2sail@quixnet.net Thanks, Bob 'Second Nature'
Attent: Henry Webber Your comment sent shivers up my spine and out through my wallet .. when you say "Nevertheless when I rebuilt my engine last year I found that the cylinder sleeve was corroded through from the outside about 75% of its thickness. You can't see it until you extract the sleeve from the cylinder. The engine had about 1200hrs and was 23yrs old." I hope this is what is likely the 'steel sleeve' used for the piston, and not the cast iron sleeve into which the liner fits ?? I'm having my SB8 rebuilt, and I would describe it like you did yours! Any other words you can add. Send off line if preferred: we2sail@quixnet.net Thanks, Bob 'Second Nature'
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