Kubota EA300

[Tanman]

There are three of these Kubota EA300s I have found for sale in my area for around $300-$500. Seems like a good deal, does anyone have any experience with them?

[old seagull man]

http://www.microcogen.info/index.php?topic=542.0

Info and manuals.

[Tanman]

Thank you.

[guest18]

Just updated the links for the service and parts manuals.

http://www.microcogen.info/index.php?topic=542.0

The original links would not open.
They should open up now.

Henry

[guest18]

The EA300 and EA330 engines are some of my favorites. Had one of each and they loved running between 2600 -2800 rpm. My opinion is both engines had more fuel knock below 2600 than I liked.

The EL300 is another one. They look almost the same.
The maximum rated rpm is 2000. I do know they are timed 22deg. BTDC. Probably to help with less fuel knock at lower RPM’s.
There might be some internal differences. Never saw the inside of one.
The EL300 would be the one to find if someone is planning to build a small slow running genset.

The EA300 might be able to run at lower speeds like the EL300 by Setting back the timing 3-1/2 degrees. And setting the governor speed to 2000.

[Tanman]

I picked up a EA300 for $300, tore into it today and found that one of the valves wiggles a fair amount and the valve seat has worn a little. I have the manuals and part numbers. It seems like parts are a little tough to find, is my best shot my local Kubota dealer hunting some valves and valve guides for me?

[guest18]

That might be your best bet. Kubota should be able to get them. While you have it apart it would be a good time to check the cylinder bore and if it’s within spec hone the cylinder and re-ring the engine.

Just in case the bore is out of spec. There is an oversized piston and rings available.

Which guide is worn?

Do you have any idea of the hours on the engine?

Henry

[guest18]

Tanman, Just received a call from a friend in Jacksonville Florida that runs a shop that makes compact diesel generators for sailboats. They use Kubota engines only.

He knows the EA300 and EA330 very well. The company made Hundreds of units with those engines.
We talked about your situation and he explained to me that it’s normally the exhaust valve guide that will get some wear over time. The intake valve guide normally don’t give any problems but since the engine does not have valve guide seals there is a possibility of having oil sucked around the intake guide if it’s very worn. This situation can be made worse with oil getting past the piston rings and if the air cleaner is restricted. He said there has been a few known cases of runaway engines but very rare.

He mentioned to replace valve guides, check valve stems and seats for wear, check cylinder and re-ring it and make sure the breather is functioning properly.

He mentioned that a good machine shop should clean up the seats. However the heads are known for rusting through on salt water applications so if it was a salt water engine check out the head thoroughly. If the head is bad a new one is available but it’s around $500.00.

When I was visiting him years ago I saw a whole bunch of EA300 heads on a table that were just rebuilt. I ask him about those and his response was the market pretty much dried up. At times they good ones on eBay for rebuilding.

Henry

[Tanman]

Thank you very much Henry, I have just ordered the parts you suggested! I will need to have the valve seats cleaned up for sure. No salt water damage but some damage from the loose valve. Thank you for the information, it helped me out a lot!

Question for folks with more experience, I’ve only replaced piston rings once on a 2-stroke four wheeler and haven’t de-glazed a cylinder before. Should I give it a go or have a shop do it?

[snowman18]

Thank you very much Henry, I have just ordered the parts you suggested! I will need to have the valve seats cleaned up for sure. No salt water damage but some damage from the loose valve. Thank you for the information, it helped me out a lot!

Question for folks with more experience, I’ve only replaced piston rings once on a 2-stroke four wheeler and haven’t de-glazed a cylinder before. Should I give it a go or have a shop do it?

if you have chrome moly rings I would let the shop do the work.

Read the full article, https://www.hastingspistonrings.com/tech-tips-faqs/cylinder-bore-refinishing

Cylinder bore refinishing is extremely important in the engine rebuild process. There are some basic rules and facts that will prevent common problems incurred when deglazing or refinishing cylinders.
Cross Hatch Angles

The correct angle for cross hatch lines to intersect is approximately 45 degrees. Too steep an angle promotes oil migration down the cylinder resulting in a thin oil film, which can cause ring and cylinder scuffling.

Too flat a cross hatch angle can hold excess oil which conversely causes thicker oil films, which the piston rings will ride up on or hydroplane. Excessive oil consumption will result.

The diagrams will illustrate cross hatch angles.

[guest18]

Very well said snowman18,  it would take an engine rebuild shop to do it right.

Henry

[Tanman]

Ended up dropping it off at the shop to have the valve seat repair, new valves and valve guides installed and lapped, cylinder honed and new rings, as well as a new rod bearing. Now while that is getting built, I need to figure out what generator head to slap on the things. I wish I could find an 1800rpm 3kw 1ph 115v brushless head, any thoughts?

[Tanman]

So the engine is back from shop, and I have it all back together. When I try to start it I get some white smoke but no fire. Any thoughts? I'm thinking about warming up the injector with a small propane torch and maybe applying some heat down the intake to see if that will get it to fire.

[sirpedrosa]

Hi tanman

I would suggest prior a wood fire by the intake manifold, or by the fuel fill cap!

Are you insane? the injector is a nanometer clearance piece of fine engineering. DO NOT MESS WITH INJECTOR! IT MUST BE PRISTINE!

ABC of Rudolf Christian Karl Diesel: diesel will ignite with pressurized amount of air, and a spray more pressurized than that air!

hammers, torches, mallets and other stuff will ruin it.

Be patient! look at it as a very fine piece of art, that you can give two turns with a handle and the magic happens.

Stay safe
VP

[Tanman]

Thanks, I ended up shooting a little hot air down the intake and it fired right up, just a little cold blooded.