YANMAR ENGINES

[zengirl]

Does anyone know the difference between a 3ym30 and 3gm30?

[gonesail]

looks like the 3YM30 is a more recent engine than the 3GM30. more torque and quieter they say. not sure if they have the same footprint.

[AA3JY]

Basically the same foot print as we where going to repower with the newer 3ym30..however the exhaust is located in a different location thus a major redesign of our cabinetry ..

[IslandHopper]

Have attached a link to the 3GM30 Ops Manual and the Tech Data sheet pdf for the 3YM30.

A few obvious differences are the YM is newer as mentioned, but also has a bit more hp (around 2) and is lighter, a quick look around indicates swapping out the GM for the YM is a fairly popular and relatively painless exercise....

https://j109.org/docs/Yanmar_3GM30F3.pdf Specs on page 11

[zengirl]

Thanks to all. I have a 3YM30 and the parts cost a fortune was wondering if some parts would fit and are cheaper. Water pump was $400, heat exchange was $800. I love my engine, just looking to get spares at a cheaper price that would do the same job.

[Wotname]

Originally Posted by zengirl

Thanks to all. I have a 3YM30 and the parts cost a fortune was wondering if some parts would fit and are cheaper. Water pump was $400, heat exchange was $800. I love my engine, just looking to get spares at a cheaper price that would do the same job.

It is unlikely that any interchangeable part would be cheaper. IME, Yanmar keeps the same part number for whatever parts that are shared between engines and the price is predicated on the part number, not the engine.

As an aside, your 3YM30 water pump will be fairly new and it can be rebuild dozens of times for peanuts. All the wear components (bearings, seals etc) are standard sizes and are available from any bearing suppliers for small dollars. The impeller will be found at most marine outlets.

[Rapanui]

As Wotname says. Every year when I change the water pump">raw water pump impeller, I remove the bearing seal and replace. No leaks and bearings last forever. Seal is 12 I'd, 24 od and 7mm deep, very cheap. Keep the raw water pump belt tension low.
The beautiful expensive Yanmar stainless exhaust elbows develop pinholes and cracks in the welds. Get the investment cast stainless ones from HDI, much cheaper and no welds.
I do use the Yanmar coolant and change every 2 years. So far after 8 years no heat exchanger problems

[a64pilot]

The Yanmar coolant is GM’s Dexcool

[zengirl]

Originally Posted by Wotname

It is unlikely that any interchangeable part would be cheaper. IME, Yanmar keeps the same part number for whatever parts that are shared between engines and the price is predicated on the part number, not the engine.

As an aside, your 3YM30 water pump will be fairly new and it can be rebuild dozens of times for peanuts. All the wear components (bearings, seals etc) are standard sizes and are available from any bearing suppliers for small dollars. The impeller will be found at most marine outlets.

Thanks for the info, I kept the old pump for a spare and if I pick up new impeller, I'll be good to go in an emergency.

[Seymore]

Originally Posted by zengirl

Does anyone know the difference between a 3ym30 and 3gm30?

A few years ago the 3GM30 design was upgraded to meet new emission standards. Yanmar labelled the upgraded engine 3YM30.

I think that, accordingly, some parts are interchangeable and some aren't.