It's starting to get cold here at night (low 30 to mid 20) so I thought I would drain my SB8 water system and my fresh water system. The fresh water tank and supply lines are no big deal, but I'm not sure about the SB8 diesel cooling system. I've had the impeller out (to inspect it) so I am somewhat familiar with the engine I found some information that stated you should close the seacock, remove the inlet and out let hoses from the water pump to let them drain and then do something else (Undecipherable) to drain the rest of the engine. Any idea what they were talking about? I could use some advice. Thanks John
Yanmar SB8 raw water system
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John
Cyl head
John, I do not know how many cylinders the SB8 has, but on my one cylinder SBY12,I reach up under the cylinder head which is horizontal and locate a brass pipe plug. Make sure it is a pipe plug. An alternate you might find may be a petcock type valve. Anyway after feeding antifreeze through my pump and engine, I remove the pipe plug and drain out any water and antifreeze in the engine. I leave it out for the winter. I have done this for 3 seasons now, and have not had any problems with the engine over the winter. BTW, I was able to download an engine manual for the YSE model engines which covers an YSB* and YSB12 engines. If I recall correctly it was the Yanmar site and each page was a jpeg file (46 pages) Good luck John
John, I do not know how many cylinders the SB8 has, but on my one cylinder SBY12,I reach up under the cylinder head which is horizontal and locate a brass pipe plug. Make sure it is a pipe plug. An alternate you might find may be a petcock type valve. Anyway after feeding antifreeze through my pump and engine, I remove the pipe plug and drain out any water and antifreeze in the engine. I leave it out for the winter. I have done this for 3 seasons now, and have not had any problems with the engine over the winter. BTW, I was able to download an engine manual for the YSE model engines which covers an YSB* and YSB12 engines. If I recall correctly it was the Yanmar site and each page was a jpeg file (46 pages) Good luck John
As simple as it gets
I'm told by a Yanmar dealer that the YSE, YSB and YSM engines were all essentially the same. They had a single horizontal cylinder, were raw water cooled & available in 2 sizes, the 8 HP ( 331 cc's) and the 12 HP (510 cc's) I have a factory service manual for the YSM's and everything looks the same as my YSB engine. The cooling system is about as basic as it gets: raw water goes thru a belt driven pump & into the cyl. head, then into the block where it exits via the thermostat housing to the exhaust. When the t'stat is closed (cold) there is a bypass hose that allows cooling water to go direct into the exhaust. Most boating magazines have detailed articles abt. winterizing in their fall issues, but in essence it involves flushing the cooling passages with antifreeze then draining the system, including the exhaust & waterlift muffler.
I'm told by a Yanmar dealer that the YSE, YSB and YSM engines were all essentially the same. They had a single horizontal cylinder, were raw water cooled & available in 2 sizes, the 8 HP ( 331 cc's) and the 12 HP (510 cc's) I have a factory service manual for the YSM's and everything looks the same as my YSB engine. The cooling system is about as basic as it gets: raw water goes thru a belt driven pump & into the cyl. head, then into the block where it exits via the thermostat housing to the exhaust. When the t'stat is closed (cold) there is a bypass hose that allows cooling water to go direct into the exhaust. Most boating magazines have detailed articles abt. winterizing in their fall issues, but in essence it involves flushing the cooling passages with antifreeze then draining the system, including the exhaust & waterlift muffler.
Undo a hose clamp
My Vetus waterlock has a drain plug on one end, at the low point of my exhaust system, but if necessary, just undo a couple of hose clamps. That probably isn't a concern in Atlanta, but I'm told that if the pink RV antifreeze is used it can freeze if exposed to a prolonged period of sub-zero weather.
My Vetus waterlock has a drain plug on one end, at the low point of my exhaust system, but if necessary, just undo a couple of hose clamps. That probably isn't a concern in Atlanta, but I'm told that if the pink RV antifreeze is used it can freeze if exposed to a prolonged period of sub-zero weather.
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Jack
Another way
I have the Universal diesel raw water cooled engine. I simply pull the raw water intake, stick it in a bucket of fresh water with a small can of radiator anticorrosion liquid (not antifreeze-not needed here), run the engine until the fresh water comes out the exhaust. Close up all valves, and she sits for 6 months with fresh water and an anticorrosive in the cooling system. 6 months later, open seacocks and start up. Been doing this for 15 years. I imagine antifreeze with the anticorrosives would do the same, but then be blown out into the water upon startup.
I have the Universal diesel raw water cooled engine. I simply pull the raw water intake, stick it in a bucket of fresh water with a small can of radiator anticorrosion liquid (not antifreeze-not needed here), run the engine until the fresh water comes out the exhaust. Close up all valves, and she sits for 6 months with fresh water and an anticorrosive in the cooling system. 6 months later, open seacocks and start up. Been doing this for 15 years. I imagine antifreeze with the anticorrosives would do the same, but then be blown out into the water upon startup.
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Kevin
Here's what I do with my YSE8
When the boat is hauled and the engine is still warm, remove the intake hose from the through hull, stick it in a 4 litre (roughly 1 US gal.) jug of pre-mixed antifreeze, start the engine and pump it through, catching the exhaust side in a bucket, to be disposed of properly. Don't bother draining out the anti-freeze as it protects against rust. But you have to flush it out and prperly dispose of it in the spring before launch. All the YSE/YSB/YSM owners I know do it this way. Kevin CS 27 with a 31 year old YSE8
When the boat is hauled and the engine is still warm, remove the intake hose from the through hull, stick it in a 4 litre (roughly 1 US gal.) jug of pre-mixed antifreeze, start the engine and pump it through, catching the exhaust side in a bucket, to be disposed of properly. Don't bother draining out the anti-freeze as it protects against rust. But you have to flush it out and prperly dispose of it in the spring before launch. All the YSE/YSB/YSM owners I know do it this way. Kevin CS 27 with a 31 year old YSE8
K
Kaizen
Winterizing diesel
Don't forget to remove the thermostat and drain the engine block before starting the engine to suck in anti-freeze. When the engine is cold, the anti-freeze won't go into the engine block. It just stay in the cylender head and out the exhaust elbow thus give you the false sense of wintering the engine. I have a Volvo Penta diesel but the theory is the same.
Don't forget to remove the thermostat and drain the engine block before starting the engine to suck in anti-freeze. When the engine is cold, the anti-freeze won't go into the engine block. It just stay in the cylender head and out the exhaust elbow thus give you the false sense of wintering the engine. I have a Volvo Penta diesel but the theory is the same.
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