Kubota single cylinder diesel

[Maxus]

So I've just picked up this old yamaguchi tracked dumper and it has a kubota oc62 engine. It's was a real pig to get started so I charged the battery overnight and today disassembled and cleaned up the starter motor. It's helped a lot, as did changing the oil!

The first question I have relates generally to small dieseI engine and is: what else can I do to improve the running of the engine? I don't think it's been properly serviced judging by the state of the old oil.

Second question is a bit more convoluted and relates to the difference between the kubota oc 60 and the kubota oc 62. From what I can gather the main difference is the position of the output shaft.

Currently I have the oc 62:

Here is oc 60:

My question is: What are the chances I can use parts of the oc62 currently installed on the machine to adapt the oc60? I can get an new oc60 much cheaper than an oc62 and it'd be nice to have a brand spanking new engine plus the old one, which works if I ever needed parts, especially as a genuine glow plug is £80 and a genuine starter is £414!!

 

[doobin]

If it’s belt drive just fit some longer belts!

The rings wear on these little engines when abused/not serviced, try adding some Lucas heavy duty oil stabiliser.

what bit of its running aren’t you happy with?

 

[Maxus]

If it’s belt drive just fit some longer belts!

Good thinking, but I'm not sure the pto is going to rotate in the same direction? I will double check this!

Runs OK to be fair, a little bit of white smoke is coming from the exhaust. Possibly unburnt diesel? Was thinking about getting injector reconditioned.

Just looking for quick wins really, im not used to working on these little dieseIs. I'll definitely look up lucas heavy duty oil stabiliser.

 

[Giles]

So I've just picked up this old yamaguchi tracked dumper and it has a kubota oc62 engine. It's was a real pig to get started so I charged the battery overnight and today disassembled and cleaned up the starter motor. It's helped a lot, as did changing the oil!

The first question I have relates generally to small dieseI engine and is: what else can I do to improve the running of the engine? I don't think it's been properly serviced judging by the state of the old oil.

Second question is a bit more convoluted and relates to the difference between the kubota oc 60 and the kubota oc 62. From what I can gather the main difference is the position of the output shaft.

Currently I have the oc 62:
View attachment 30368

Here is oc 60:
View attachment 30369

My question is: What are the chances I can use parts of the oc62 currently installed on the machine to adapt the oc60? I can get an new oc60 much cheaper than an oc62 and it'd be nice to have a brand spanking new engine plus the old one, which works if I ever needed parts, especially as a genuine glow plug is £80 and a genuine starter is £414!!

I sold one for £200 not long ago they use them in traffic lights a lot I bought one to convert petrol track dumper to diesel

 

[V8Druid]

Good thinking, but I'm not sure the pto is going to rotate in the same direction? I will double check this!

Runs OK to be fair, a little bit of white smoke is coming from the exhaust. Possibly unburnt diesel? Was thinking about getting injector reconditioned.

Just looking for quick wins really, im not used to working on these little dieseIs. I'll definitely look up lucas heavy duty oil stabiliser.

invest in a tub of injector cleaner/UCL additive first ... you never know what a few fuel treatments might produce

 

[Gecko]

Pretty sure the "offset" output is driven off the camshaft giving you a 2:1 reduction on a counter-rotating shaft.
Your dumper will go backwards really fast!!

An alternative engine (drop in, but not parts compatible) is the Yanma L-series which is also available with the reduction PTO shaft.

 

[Canal Navvy]

Pretty sure the "offset" output is driven off the camshaft giving you a 2:1 reduction on a counter-rotating shaft.
Your dumper will go backwards really fast!!

Even longer belt with a twist in it

 

[V8Druid]

Even longer belt with a twist in it

did think of that, but the belts take a caning where they cross unless you can install a separator idler of some sort

 

[Maxus]

Pretty sure the "offset" output is driven off the camshaft giving you a 2:1 reduction on a counter-rotating shaft.
Your dumper will go backwards really fast!!

An alternative engine (drop in, but not parts compatible) is the Yanma L-series which is also available with the reduction PTO shaft.

Looks like you are right:

Seems like it's would be hard to adapt a new oc 60. Do you think it's possible? I suppose there only one way to find out..

It's certainty not worth spending 2-3k on a new engine.

 

[Mick-the-fitter]

What is driven by the belts? Guessing a hydrostatic pump or the belt is used as a clutch!

 

[Maxus]

What is driven by the belts? Guessing a hydrostatic pump or the belt is used as a clutch!

It's belt drive. Two sets of belts. One set of belts drives a gear box and the other set drives a hydraulic pump. Pump powers two rams that tip and lift the skip. Yes belts act as a clutch, similar to how a woodchipper blades engages.

The drive shaft on the common oc60 rotates counter clockwise and is an extension of the crankshaft, the engine on the machine itself, is a somewhat rare oc62 EGBX, the drive shaft rotates clockwise and is an extension of the crankshaft. Not sure if they both spin at the same RPM..

The current engine is hard to start, looking at ways to improve this if you have any suggestions. I've cleaned starter motor inards and will replace worn brushes, added injector cleaner to the fuel, changed oil and will do this again adding lucas oil stabiliser, ordered and will install new fuel filter. I am considering sending of the injector to be reconditioned, but will see if the injector cleaner has any effect. Suspect that possibly piston rings may be worn and low compression could be causing hard start... a little bit of white smoke is present from the exhaust when under heavy load.

It's been interesting familiarising myself with diesel technology!

 

[Gecko]

If it's had a hard life with minimal maintenance, I'd be pricing a new injector as an alternative to rebuild.

Hard starting and smoke under load makes it worth checking the injection timing (Page S-15) http://www.kubotabooks.com/AutoIndex/index.php?dir=Engines/&file=WSM_OC60[1].pdf

 

[Mick-the-fitter]

Has it ever been apart do you know? ie has the head been off? Although the crankshaft would turn in different directions, there is such a thing as an opposed rotation engine, but the speed of the camshaft against crankshaft would be half the speed unless the pulley sizes were changed!

 

[Mick-the-fitter]

What is driven by the belts? Guessing a hydrostatic pump or the belt is used as a clutch!

the internals are very similar if not identical to the Yanmar L70 even down to the cover gasket!

 

[Maxus]

Has it ever been apart do you know? ie has the head been off? Although the crankshaft would turn in different directions, there is such a thing as an opposed rotation engine, but the speed of the camshaft against crankshaft would be half the speed unless the pulley sizes were changed!

I have no idea, it's fairly old so it's possible. I've seen lots of videos of them being disassembled and reassembled, mostly in the far East by children!

A new injector is £150 and a new fuel pump is £450 or I can get them reconditioned for £40 and £130 respectively. Alternatively I can buy a 'new' oc60 of ebay for £1k and use it for parts.

I will certainly follow Gekos suggestion and check fuel pump timing, not sure where to get the shims though

 

[doobin]

You could just put a petrol Loncin engine on it.

 

[Russell]

I had the same problem with my old oc95e. It wouldn't start without easy start/ brake cleaner.
I pulled it apart the the bore was perfect with clearly visible crosshatching with no wear.
I sold it in the end and changed for a petrol because it's a horrible noisy vibey engine.
The person that bought it put a new injector and pump on it and said it was fine after.

 

[Gecko]

not sure where to get the shims though

Fortunately, if you are compensating for wear, you need to remove shims, not add them.

A beer can, dress-makers scissors and an office hole punch (for the bolt holes) is all you need to make passable shims.
If you can't find an empty, you'll just have to force yourself.

 

[Maxus]

So, thought I'd update. Had a good go at the engine over the weekend and she's now starting and running perfectly.

Not sure what exactly did the trick but after delicately cleaning a bit of soot off the injector tip with carb cleaner, replacing the fuel filter and using a product that cleans the valves she starts easily and runs with no smoke what so ever.

My guess is that the intake cleaner did the trick. Worth trying if you have any diesel engines that are running a bit rough I'd say. Cautrac, suppliers/importers of the machine, were very helpful when I contacted them.

 

[Bri963]

It's belt drive. Two sets of belts. One set of belts drives a gear box and the other set drives a hydraulic pump. Pump powers two rams that tip and lift the skip. Yes belts act as a clutch, similar to how a woodchipper blades engages.

The drive shaft on the common oc60 rotates counter clockwise and is an extension of the crankshaft, the engine on the machine itself, is a somewhat rare oc62 EGBX, the drive shaft rotates clockwise and is an extension of the crankshaft. Not sure if they both spin at the same RPM..

The current engine is hard to start, looking at ways to improve this if you have any suggestions. I've cleaned starter motor inards and will replace worn brushes, added injector cleaner to the fuel, changed oil and will do this again adding lucas oil stabiliser, ordered and will install new fuel filter. I am considering sending of the injector to be reconditioned, but will see if the injector cleaner has any effect. Suspect that possibly piston rings may be worn and low compression could be causing hard start... a little bit of white smoke is present from the exhaust when under heavy load.

It's been interesting familiarising myself with diesel technology!

If you still have an injection shop nearby, let them put your injector through the ultrasonic bath. You can have an un-worn injector with a bad spray pattern due to carbon build up round the nozzle. Bit like having a bit of mud in the end of a pressure washer.

on edit, just seen your last post Maxus. You got there before I did