Repairing engine that has low compression

[Romario]

I have an engine that is based on Kubota, it is in my boat, Universal 5416. It is based on Kubota Z751 block.

I suspected that there was a problem with fuel system, but it looks like the problem is elsewhere - I checked the compression and it was 200 in both cylinders, far lower then recommended minimum of 325.

The engine was running and starting without much problem before it stopped working, I though the problem was with fuel system (there was a hose that was leaking air), but after replacing every part of the fuel system it didn't work.

I replaced the head as well since the valves were leaking and I though that was the problem, but even after that the compression is too low - 200 psi.

Here is another topic with more details of what I did:
http://www.orangetractortalks.com/forums/showthread.php?p=109446

So, my question is now - how do I fix the problem I have? I guess I need to replace the rings. Can the forum recommend me someone, preferably in Long Island, NY or close by who can fix the engine?
I am looking for someone who can take it and make it run. It will most likely mean replacing the piston rings and doing whatever else that needs to be done.

I would also like to know how much will it cost approximately.

My upper range in price is this re-manufactured engine:
http://www.dieselenginetrader.com/engines/engine_details.cfm?id=16381

I don't really want to pay that much, just indicating the upper range.

 

[Wayne64SS]

Did it ingest water or some other type of liquid and hydralock bending the rods? You didn't bother to check piston protrusion or anything in the bottom end when you had the head off?

 

[Romario]

Did it ingest water or some other type of liquid and hydralock bending the rods? You didn't bother to check piston protrusion or anything in the bottom end when you had the head off?

I don't think it ingested water, I had water problem though - someone tried to steal the fuel from the boat and they didn't close the fuel cap, so I had a lot of water in the fuel tank and I think it might have made it way lower. I noticed that though before starting the engine and I got rid of the water in the fuel system.

I am also pretty sure I closed the valve that goes from the tank to the engine, but I don't remember now, it was a year ago.

I didn't check the piston protrusion when the head was off.

 

[Romario]

So, anyone knows good mechanic in New York state? Could be NJ or CT too, but I would prefer Long Island.

I found this guy:
http://www.thomas-auto.com/

and he seems to know what he is doing, but he can't give a quote before he determines what needs to be done.

 

[rentthis]

I doubt you will find a diesel guy that can give you a price without getting into the job. There are to many variables. 200 lbs of compression indicates that you might have a lot that needs to be done. Keep in mind that when you are on a tractor and it quits, there you are. In a boat and it quits, where are you? $3800.00 is a lot when you are in the marina. It's cheap when you engine quits at sea..

 

[coachgeo]

Check valve clearance. Valve leakage will throw you compression way off too.

 

[Romario]

I doubt you will find a diesel guy that can give you a price without getting into the job. There are to many variables. 200 lbs of compression indicates that you might have a lot that needs to be done. Keep in mind that when you are on a tractor and it quits, there you are. In a boat and it quits, where are you? $3800.00 is a lot when you are in the marina. It's cheap when you engine quits at sea..

That's understandable. The question is - do I even want to do anything with it, or just get rid of the boat or get a new one.

I already replaced the head, so it's in the cylinders now I would guess.

 

[Romario]

Check valve clearance. Valve leakage will throw you compression way off too.

I adjusted the clearance and the head was replaced.

 

[North Idaho Wolfman]

Considering that you have the same compression with a new or rebuilt head I'm guessing that you have a bottom end issue.
I would venture to say you would probably be better off either installing a rebuilt engine as just good quality rebuild parts will run you in the thousands also plus labor, or as you said sell the boat and move on.

 

[Romario]

So, finally the mechanic I found got to the engine and he is saying he has problems finding parts. Here is what he is asking:

- what is the cylinder wall size. Max clearance between the piston and the wall.
-Standard piston size diameter (ie, 10-over, 20-over, etc). What is the maximum oversize?
- crank journals, what is the size crank minimum and maximum? What size oversize bearings?
- rods in block. Min max.
- means in block. min max
- connecting rod itself. What is the size of the whole, what is the size of the rod?

Mechanic says it if we are able to talk to somebody else knows what they're talking about, mechanic will be happy to talk to the person directly if we give him the number.

Mechanic also said he went to Kubota and he was sent to Cherry Valley, which sent them to country sales. They'll say the motor is obsolete which is why charlie is tracking down parts that will just fit.


So, if someone can recommend a dealer who knows what needs to be done and what parts need to be acquired it would be perfect.
Or at least documents about rebuilding.

 

[coachgeo]

...
So, if someone can recommend a dealer who knows what needs to be done and what parts need to be acquired it would be perfect.
Or at least documents about rebuilding.

Parts break down with drawings and part numbers (tractor version w/same engine)

. Go here http://www.kubota.com/part/parts.aspx
. Hit the [Illustrated Parts list] button
. accept the legal thingamabob
. Hit [OPEN]
. type in [ L185 ] (tractor model with same engine)
. Select the 185F
. Open the "Engine" section.

Here is an old copy of above BUT..... above will NOT have some of the superseded part n#'s that pdf manual below will not have

http://kubotabooks.com/AutoIndex/index.php?dir=Tractor Parts Manuals/&file=L185F.pdf

With these part numbers you can get the parts from anyone who sells Kubota engine parts.

For engine rebuild
here is some general stuff (scroll down to L185):
http://kubotabooks.com/AutoIndex/index.php?dir=Engines/&file=Kubota engine specs.pdf

PM me your email and I can attempt to send you the Generic "workshop manual" for repairing the engine in the L185 tractor's engine along with others that are similar.


Ohh and is this the 5416 M20 Universal? If so try

http://www.marinedieseldirect.com/c...intparts=200140&printservice=&printoperators=

also if it is the M20 or M30 here is your service manual

http://www.marinesurveyorontario.com/universalatomicdiesel.pdf

 

[ShaunRH]

Sounds like it's time for new sleeves, bearings and oversize at that to handle the grind down.

I have to do this to my D17's Buda 262, a full rebuild, to bring the engine back. Staring at $3000 with me doing all the work! It's not cheap.