Kubota Generator Rebuild

[brantleychuck]

I picked up a phasor LP2-6.0KW GENERATOR for $200. I bought it from a sailor that bought it from the original owner. The original owner said it ran fin but was getting harder and harder to start. The guy I bought it from could not get it to start, took it to dealer and they said " needs a valve job and rings".

H


Sent from my iPad using Cruisers Sailing Forum

[brantleychuck]

I got it home and attempted to turn it over by hand. The crankshaft would move but would come to a pretty hard stop, Turing in either direction. Then I noticed the intake manifold was corroded away on the side of it. It was very close to the heat exchanger. It looks like a long time slow leak of seawater got to it. At this point I thought it best to pull the head because of all the material that must have got sucked it the combustion chamber from the corroded manifold. First I pulled the glow plugs just to make sure compression was not what was keeping the crank from going all the way around. With the plugs it the engine still did not turn all the way around. Everything felt smooth with no clunking sound when it came to a halt.. Here is a picture of the intake manifold


Sent from my iPad using Cruisers Sailing Forum

[brantleychuck]

It was pretty easy to get the head and pistons out, about a hour. After the head was off I did not not see anything in the combustion chamber that would stop the crank from turning, like a big chunk of intake manifold. I turned the crank again at that point and ant it turned freely. There is a lot of carbon build up on top of the pistons, one more than the other. I believe this build up is what stopped the engine from turning.
The cylinders have no scratching and I can not feel a lip or any deformities in the cylinder walls. The pistons look good as well with little signs of wear. There are no hatch marks showing. My plan at this point is to do some measuring of the cylinder walls, pistons to see if they are in spec. Get a bead hone and see if I can bring the cylinder walls and create some cross hatch.


Sent from my iPad using Cruisers Sailing Forum

[brantleychuck]

I forgot to mention that I noticed one of the valves rockers arm adjustments was. Way way loose. One of the exhaust valves looks lower in the combustion chamber than the rest. I will need to pull the head apart and inspect. Also feel I better check the cam shaft lobes to make sure that was not the cause of the large rocker arm clearance adjustment. I'll include a picture of the intake ports on the head, lots of gunk in there from what assume was the corroding intake manifold.


Sent from my iPad using Cruisers Sailing Forum

[brantleychuck]

Thought one valve was lower but actually one exhaust valve was higher. It was stuck partially open. A slight tap lowered it.maybe sitting around not running caused that. I will disassemble head and inspect. May try to hand lap valves and see how that looks.
Working on getting some parts sourced. First problem is that I could not find any serial or model numbers stamped on engine. I do have a bronze plate that Phasor attached to engine with model and serial. I talked to Mary at phasor and she is going to call me back with the part numbers I need. She can't sell parts outside Florida. So a bit of good customer service out of Phasor. ! Chuck


Sent from my iPad using Cruisers Sailing Forum

[a64pilot]

Maybe the piston was hitting the stuck valve

[brantleychuck]

Very likely it was the sticking valve. Good call. I've already cleaned the pistons so any evidence is gone. No marks on piston top. The sticking valve does solve the loose rocker adjustment mystery.


Sent from my iPad using Cruisers Sailing Forum

[brantleychuck]

The head is at the machine shop for a valve job. I've ordered the piston rings and gaskets. Also ordered a bead hone and a tool to measure the cylinder walls.
Here is a picture of the culprit


The end cap on the heat exchanger has been damaged in the past. Looks like damage was caused trying to remove the cap. I have damaged it more myself trying to remove. I'm guessing it un screws? Anybody have any experience with this heat exchanger, getting the cap off?


Sent from my iPad using Cruisers Sailing Forum

[Blue Stocking]

Must be a million of those engines in use. Try a Tractor Supply, or similar, for parts for better prices than marine.

[a64pilot]

Originally Posted by brantleychuck

The sticking valve does solve the loose rocker adjustment mystery.


Sent from my iPad using Cruisers Sailing Forum

It could, see as the cam profile drops and normally the valve closes, but in a stuck valve since it it is the valve spring that keeps clearances tight, if the valve was stuck open when the cam was in a position it should be closed, there would be a lot of slop. Remember these are not desmodromic valves, these use a spring to close and keep pushrods and rockers tight.

[a64pilot]

Don't use a dingle berry hone, you can probably get a machine shop to put a light hone on it for next to nothing

[jimbunyard]

Rebuilt an older (1995) LP1 at the beginning of the year, the heat exchanger looked very similar, if not identical. The old style are soldered on, the new style has removable end caps. If you have a radiator shop in your area they can check and service it. Or if you have a propane torch with a Mapp gas cylinder you can probably get it off. You could also pressure test it yourself by plugging the inlet pipe, putting a hose on the outlet pipe, submerging the whole exchanger in a tube of water and blowing (10 psi or so) air into the hose. Any leaks will blow bubbles.

Don't know where you're located, but there's a Kubota ZB600 engine on San Antonio craiglist now for 100.00. The ZB600 is the base engine for the LP2. Not marine but it looks like you might need an intake manifold.

Also, since you're in there and they're cheap, why not replace the rod bearings too? Seems a false economy not to...

[brantleychuck]

Wish I could grab that kubota in San Antonio . I'm in so cal. I could use the intake. I may just make one. Going to be passing through San Antonio mid November. I'll call when I am passing through and see it it still for sale. I was thinking the same thing about the rod bearings even though the show no vis able wear. I went ahead and ordered those today. Thanks for the info on the heat exchanger, did not think about the cap being soldered on but it is. I thought that you needed access to the core for occasional cleaning. I'm going to hold off on pulling the heat exchanger apart until I find out how this all works out. I run it first and see how she does. Looks like a couple weeks to get parts in hand.







Sent from my iPad using Cruisers Sailing Forum