yanmar ysb8 / ysm8

[hurley]

hi Would anyone know if the engine footprints are the same for these two engines. I am considering getting a YSM 8 as a direct swap for the ysb8 in my existing boat.

Ideally I would like to be able to use the existing propshaft etc.

My rationale is that I have sufficient mechanical skills to be able to do a straight engine swap thus keeping everything economical (at least in money terms)

Thanks in advance for any advice.

 

[MrCramp]

I found the following site very usefull when I had a Yanmar 2GM20. The information that you want might be burried in the site somewhere, or the people who run it might tell you the answer to your question.
http://www.yanmarhelp.com/index.htm

 

[VicS]

There are some manuals HERE which may be of interest

 

[l'escargot]

I am not familiar with Yanmars, but as far as I recall YSB was one made with aluminium gearbox they only made for a year or so, then modernizing (so it's YSM) by giving new injector pump and dispensing with chain starting system - but on the same engine block probably. Don't know of any major change in basic design. I may be wrong at this; but a good chance it will fit.
I should still have a service manual for YSM; dimensions are there, so if You want it - give me a message - it's big file.

I think you will find the YSE was the one with the aluminium gearbox that then evolved into the YSB - I know they had the same footprint because I replaced a YSE with a YSB myself. The YSM came next and whilst still a horizontal cylinder (hence the Y prefix) it looked quite different although I can't remember what was changed - I think the water pump changed sides and the alternator was moved as well. I am not sure about the footprint although I have an idea that it was different.

I've got photos and manuals somewhere on another computer, I will try and find them and see if I can come up with a definitive answer in a day or two.

 

[hurley]

hi thanks for taking time to help its much appreciated.

yes agree that the water pump was switched to other side and also the objectors pump design and location changed.

it would be great for any thoughts about footprint and also the length of engine so I wouldn't then need to modify propshaft length.

thanks so far guys !

 

[SEAPAINTER]

hi Would anyone know if the engine footprints are the same for these two engines. I am considering getting a YSM 8 as a direct swap for the ysb8 in my existing boat.

Ideally I would like to be able to use the existing propshaft etc.

My rationale is that I have sufficient mechanical skills to be able to do a straight engine swap thus keeping everything economical (at least in money terms)

Thanks in advance for any advice.

Did you ever get an answer to the question as to the foot print for replacing an YSB8 with an YSM8?
I have a rebuilt YSM8 that I would like to install to replace my old YSB8 - 1977.
But the mounts do not seem to line up as I measured them.
I can return the YSM8 if I cannot get it to mount properly but it is a nice engine and runs - so my question is - Did you have any problems replacing your YSB8 with the YSM8?
Any information would be very helpful right now.
Thanks -

 

[hurley]

Hi sorry I can't really help you as I sold that boat and the old but new too me unused ysm 8. I believed at the time that it would have been a straight swap but unfortunately I can't confirm it. Good luck with your project. Bw Nick

 

[hurley]

You could try ringing French marine at Levington as they deal with yanmar engines and may be able to advise.