YSB8 Idling

[njwtech]

I have never owned a boat with an inboard motor before. I just bought a beautiful old Watkins W27 and it has a Yanmar YSB8. Of course being new to this type of motor and this boat I am over-thinking everythiing. I took this video of the exhaust with my motor running at the dockside. Could anyone offer an opinion if all seems well here? The motor does not smoke and it starts and seems to run well. The alternator belt needs to be tightened, but otherwise I can't see anything wrong.

Also, in the attached photo from the engine room it looks like the line from the water jacket enters the exhaust manifold in such a way that water from the coolant system would get back down into the cylinder at shutdown. Am I missing something? I would think one wouldn't want coolant water sitting in a cylinder.

Last question... I can't find numbers on the Fram cartridge fuel filter in the pictures. Does anyone know what model of cartridge it takes? The boat is a 1978 model if that helps.

Thanks for your help.

 

[klemsaba]

I have never owned a boat with an inboard motor before. I just bought a beautiful old Watkins W27 and it has a Yanmar YSB8. Of course being new to this type of motor and this boat I am over-thinking everythiing. I took this video of the exhaust with my motor running at the dockside. Could anyone offer an opinion if all seems well here? The motor does not smoke and it starts and seems to run well. The alternator belt needs to be tightened, but otherwise I can't see anything wrong.

Also, in the attached photo from the engine room it looks like the line from the water jacket enters the exhaust manifold in such a way that water from the coolant system would get back down into the cylinder at shutdown. Am I missing something? I would think one wouldn't want coolant water sitting in a cylinder.

Last question... I can't find numbers on the Fram cartridge fuel filter in the pictures. Does anyone know what model of cartridge it takes? The boat is a 1978 model if that helps.

Thanks for your help.

My wife and I bought our first boat last summer with a YSM8. The water exiting the exhaust is very similar to your video. Like yours it doesn't smoke and starts right up... when it's warm outside. When it's cooler the Yanmar takes some extra time to get going.

I've often wondered if this was normal as well and look forward for others to chime in.

I can't comment on your other questions.

 

[David in Sandusky]

Sounds normal

Sounds normal to me. Closing the fresh water intake valve prevents a leak from sinking the boat, but on this engine, it also prevents filling of the cylinder via the piping you describe.

Our SB8 did a great job for us through the last 10 years of its 30 year life, then died of a cracked head. In the last years, the rings were allowing enough blow-by to reduce power by about 20%. But she would drive our '77 h27 at 4.5 knots forever, and it was all we needed to get in and out of port.

 

[kloudie1]

njwtech.. I have a primary filter like yours (I think) .. It originally had a really strange element in it and I can't find that element any longer. The element that fits it is a Fram C-1110 PB, or a NAPA 3110.. You can get these at auto parts places. The original element was made of small flat, thin cardboard strips like small Popsicle sticks.. They were laid flat and made into a tall hexagon to fit inside the container. A filter element was enclosed inside the hexagon. I think it was to help separate water.. I have looked a lot for the correct element, but all I could find is the filtering part and not including the hexagonal part. I dunno .. If you find a hexagonal element inside, take some pictures !!
Exhaust looks normal.
There is an internal baffle that directs the water in the elbow over the hump and dumps it on the downhill side.. The water cannot get back into the engine unless it back-siphons .. There should be a vented loop above the elbow .. The outlet water would go to the loop then down to the elbow.. Good luck ..

 

[njwtech]

Thanks everyone for your helpful answers. Went back up to the boat yesterday and we ran it up in gear tied to spring lines to see what it does under load and it was quite different. At full throttle lots of black smoke and soot coming out the exhaust and a sheen on the water behind the boat. Looks like it's using more fuel than it can burn. Now I just have to figure out how to clean that up. I have 100 miles to motor down the ICW to get the boat down to its next moorage, so it would be nice if I wasn't wasting fuel and leaving a cloud behind me all the way. I'm hoping it runs cleaner when not tied to the dock. Also not sure how old the fuel is that was in the tank. That might be part of it as well.