Can I turn over a Kubota diesel engine by hand?

[marrt]

I have a Kubota D1105 engine in a ZD1211 mower. When I tried to start it for the first time this year, the starter made a clicking sound. I knew the battery was going bad as it was getting slow to start last year, so I replaced the battery. However, when I turned the key over, the engine still wouldn't start, and I could hear an odd sound coming from the starter.

Since the mower was new, I've suspected this engine may have a head gasket problem because I've been losing coolant, although there's no white smoke. The coolant loss was only a few ounces over the course of a mowing season. However, having tried to start a hydrolocked engine in the past and ruining it (it was a gas engine with a defective needle valve), I didn't want to take any chances.

So, I took the hood off and tried to turn the engine over by hand at the flywheel, but it wouldn't make a complete revolution. I still think the root problem is electrical, but I want to make sure the engine isn't hydrolocked. So, my question: is it even possible to turn one of these small Kubota diesels over by hand without loosening the injectors?

 

[Skeletor]

not sure but I wouldn’t think so.

 

[murphy1244]

If you could . I wouldn't want to meet you in a alley.

 

[ptsg]

Yes, you can turn by hand, specially if you have access to the flywheel to give some more leverage. Otherwise a wrench on the crankshaft nut will do the trick. Don't force it though. Sounds like it may indeed be hydrolocked.

 

[azbinder]

Pull the glow plugs and then see if you can turn it over. Watch for any coolant coming out of the glow plug holes.

 

[4570Man]

The starter on my front deck Kubota is on its last leg. Sometimes I have to turn the flywheel a little bit to give the starter a better chance at engaging. The flywheel sticks out the back on the F series and you have good access to grab it and it’s not that hard to turn by hand. I’ve never tried to spin a full revolution by hand. I’m not sure if you could overcome the compression cycle but it’s not hard to spin a little bit.

 

[mikester]

 

[RjCorazza]

I have a Kubota D1105 engine in a ZD1211 mower. When I tried to start it for the first time this year, the starter made a clicking sound. I knew the battery was going bad as it was getting slow to start last year, so I replaced the battery. However, when I turned the key over, the engine still wouldn't start, and I could hear an odd sound coming from the starter.

Since the mower was new, I've suspected this engine may have a head gasket problem because I've been losing coolant, although there's no white smoke. The coolant loss was only a few ounces over the course of a mowing season. However, having tried to start a hydrolocked engine in the past and ruining it (it was a gas engine with a defective needle valve), I didn't want to take any chances.

So, I took the hood off and tried to turn the engine over by hand at the flywheel, but it wouldn't make a complete revolution. I still think the root problem is electrical, but I want to make sure the engine isn't hydrolocked. So, my question: is it even possible to turn one of these small Kubota diesels over by hand without loosening the injectors?

I don't know about your coolant issue, but the starter problem may be fixable with an add on starter relay. Low voltage to the starter solenoid can cause intermittent (or constant) start failures with the solenoid just clicking. I have installed these on multiple diesel mowers.
As far as turning them over by hand, I routinely turn mine over at least a small amount when greasing the shafts.
I did have an aggravating coolant loss issue when my zd1211 was new. After several months of searching, I found the lower radiator hose was leaking at a clamp... But only at a particular point in the warm up process.
Here's the wiring for a starter relay if you're interested:

 

[ericm979]

The compression ratio is roughly double that of a gas engine. So there will be a lot of resistance. I'd say there little chance of doing it by hand, and its marginal with hand tools. It'll depend on how much leverage you have and how strong you are.

If you think it's hydro locked then remove the glow plugs and turn it. I think hydro-locking happens a lot more on internet forums than in real life. Your problem is probably caused by something else.

 

[marrt]

Update. I removed the glow plugs and injectors, then attempted to manually rotate the flywheel. It moved to a certain point and then stopped. Next, I reversed the direction, moving the flywheel backward until it reached a stopping point. Following that, I used a Power Probe to actuate the solenoid by applying a positive 12.7 volts from the new battery. The engine would spin to the same position as when moved by hand but would cease to rotate beyond that point. I repeated this process several times with someone seated and all interrupt switches in the correct positions, including the parking brake engaged, both hand controls open and in neutral, the PTO switched off, etc....

I checked the oil level and it's about 1/2 inch too high on the dipstick. However, we just changed the oil before trying to start the engine and there's not a lot of oil in the filter. The engine currently contains a total of four quarts of oil, which is slightly less than what is specified in the manual.

At this point, I'm not sure what to try next.