Marinized Kubota Engine . . . What Are the Differences ?

[micheck]

What are the differences between a marine kubota/yanmar .... diesel engine and a standard tractor kubota engine?

Charles

[Sailmonkey]

instead of a radiator they have a seawater heat exchanger........other than that, nil.
I buy kubota parts from a tractor dealer........

[Mark Zarley]

Add to the list water pump">Raw water pump, exhaust mixing elbow with high temp sensor (could be a totaly different exhaust manifold), antifreeze expansion tank, and a much better intake manifold than what is on the marinized version.

[tropicalescape]

Are Kubota and Yanmar the same engine ?

[bil56]

Originally Posted by tropicalescape

Are Kubota and Yanmar the same engine ?

not at all,

both are japanese,
both are mounted on ground quipments,
both are mounted as marine engines,
both are robust and reliable

[Target9000]

Originally Posted by bil56

not at all,

both are japanese,
both are mounted on ground quipments,
both are mounted as marine engines,
both are robust and reliable

Get a price list for common parts from a kubota dealer such as Beta Marine and then compare the same parts for a Yanmar. You'll find the difference.

[alansmith]

As others have opined Volvos are very expensive repairs and difficult to get parts for...especially on this big pond called the Pacific.

Before you really feel about replacing the diesel...make sure it needs to be replaced. Diesels can be very hard beasts if treated well. Putting a new engine is not only expensive...but can involve new motor mount sleds being built under the engine, rewiring, exhaust elbows, alternator differences, mounts, piping, hook up to the drive shaft...on and on. Not to be taken lightly (economically speaking)!

I recently went to the Oakland Boat Show and spoke at length to a the Beta Marine people. The Kubotas are the shizzle. Like others have said...excellent support on west coast and Pacific basin, cheaper prices for repairs and parts, and excellent reputation amongst the boating community.

[roverhi]

Yanmar and Kubota both are primarily tractor and industrial engine manufacturers. Yanmar is marketed in the US and rebranded by John Deere. Kubota sells under their own name in the States. They are not the same the engines but are similar because they are designed for similar use. Kubota sells their engines to companies that marinize them like Beta and others. Yanmar does that in house and sells under their own name. Marinizing includes a heat exchanger different exhaust manifold, and raw water pump. You can also buy them with raw water cooling which does away with the heat exchanger and possibly the raw water pump and are cheaper.

[Jim Cate]

While both Kubota and Yanmar build and sell tractor engines etc, there are some differences of approach re design philosophy for small marine diesels between the two companies.

Most new yanmars in the ~<75 hp range are lighter weight and run at considerably higher rpm than the equivalent Kubota. Some folks like that feature, others view it as a drawback. I personally prefer a bit more displacement and lower engine speeds, and am pretty happy with my Kubota based Nanni 43 hp. This is a simple 2 litre tractor engine which is red-lined at 2800 rpm. I believe that the similar hp Yanmar is a bit less displacement, and is red lined at 3600. Yanmar owners correct me if I'm wrong here...

At any rate, most any modern marine diesel, if maintained and run reasonably will last for many, many hours. The routine maintenance does vary between marques, though... eg, Yanmar views their exhaust mixing elbows as a regular replacement item on some engines. These are pricey and IMO should last a hell of a lot longer than what Yanmar figures! The one on my engine has over 4000 hours usage and seems fine.

I believe that in most all cases, the parts most likely to cause problems are not the basic tractor engine bits but the marinization add-ons. Sadly, these are the ones you can't buy at the tractor store! They have that dread word"marine" attached to them... you know, the tag that triples the price!

The above is not represented as expert opinion, just one developed over a lot of years of observation, and of listening to folks bitching about engine problems.

Jim

[colemj]

Originally Posted by Jim Cate

Most new yanmars in the ~<75 hp range are lighter weight and run at considerably higher rpm than the equivalent Kubota. Some folks like that feature, others view it as a drawback. I personally prefer a bit more displacement and lower engine speeds, and am pretty happy with my Kubota based Nanni 43 hp. This is a simple 2 litre tractor engine which is red-lined at 2800 rpm. I believe that the similar hp Yanmar is a bit less displacement, and is red lined at 3600. Yanmar owners correct me if I'm wrong here...

Jim,

This isn't universally true with Kubota - it depends on the specific base engine. The 10-35hp range Kubotas typically are governed to 3600rpm, while the larger ones are 2800.

Mark

[ghostyman]

I am marineizing a Kubota Z482 into basically a Beta 14. I have learned that the serial number is everything. If you have a branded Kubota, you cannot buy parts from Beta. The same for Deere or Kubota. You need to provide the S/N when ordering parts, if it is not correct to your provider you are out of luck. I have found parts and willing to share info if asked. Here are pictures of what I have so far.[ATTACH]109364[/ATTACH



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[delcrest]

HI, what bell housing are you using on the picture above. PM sent

[ghostyman]

Try these people:
http://www.hayescouplings.com/mobile...Irrigation.php


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[Panope]

Originally Posted by Jim Cate

v

Most new yanmars in the ~<75 hp range are lighter weight and run at considerably higher rpm than the equivalent Kubota. Some folks like that feature, others view it as a drawback. I personally prefer a bit more displacement and lower engine speeds, and am pretty happy with my Kubota based Nanni 43 hp. This is a simple 2 litre tractor engine which is red-lined at 2800 rpm. I believe that the similar hp Yanmar is a bit less displacement, and is red lined at 3600. Yanmar owners correct me if I'm wrong here...
Jim

Jim: At some point, Yanmar reduced the red-line for many of their engines in this size range. I have a J3H3E of 40 hp (circa 1999) and it indeed has the 3600 r.p.m. red line that you stated. The current offering from Yanmar in this size is the 3JH5 of 39 hp and it red lines at 3000 r.p.m.


Another difference is physical, external dimensions. For most installations this is not a factor. However a recent design I was working on required the absolute shortest engine. By an inch or two, the Yanmar 3YM30 was found to be shorter than any other engine of that horsepower.

Steve

[brownoarsman]

I was told, but can't confirm, that universal's marinization of kubota blocks was limited to the wet exhaust manifold, the water pump (jobbed out to Sherwood), and the freeze plugs.


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