Forum for air cooled diesel engines and clones

[thepumpguysc]

They have a “low oil” shut down on them..
If it has a screw-in dipstick, do not screw it in when checking the level..

 

[90cummins]

If the compression is only 16 bar
233 psi it is too low. Remove valve cover and check for a tight valve if valves are tight adjust if needed.
It’s possible the valve adjustment loosened and the push rod is not in place. Check those & report back.
90cummins

 

[shanana]

Thank you for your replies.
The valves are checked for clearance and are ok and tight.
Pushrods are in place. The decompressionlever works correct.
I attached a picture with the smoke leakdown detection

 

[90cummins]

Hmmmmm!
How was engine running prior?
Was it under a heavy or light load for extended period?
I repaired one several years ago for a contractor who was using the same model generator to power his tools while building an addition in the summer. Basically it was under little to no load for a few weeks.
It was running fine then stopped. Same symptoms would crank with low compression.
During teardown I found valves & seats a bit dirty & rings & cylinder glazed. I cleaned the valves not sure if I ground the seats & replaced the rings & honed the cylinder. & it started & ran fine.
These engines do not like to run under light load.
Based on the compression you reported that’s the problem.
Pull head & get back to us.
90cummins

 

[shanana]

I finally managed to get the head off.
Nothing to see unnormal for me.
I tried some breakcleaner to the intake and had some light dripping through the closed intakevalve. Not much but something

 

[90cummins]

There should be no leakage between valve & seat. Remove valves to see if there is something between valve & seat. Then use lapping compound to clean & verify proper seal. Results will dictate next move.
90cummins

 

[shanana]

The valves and seats look good. I will refit them after lapping. The leakage was minimal. Also no exhaustgases in the intake

 

[90cummins]

The seats are dirty/pitted and I’m guessing the intake valve has a spot that looks burned. Absolutely no fluid should leak by the valve & seat. Diesels are very sensitive to loss of compression. If this was a 6 cylinder engine you may not notice it but a 1 cylinder engine must be in near perfect condition to start cold.
Use compound to lap valves if they don’t completely clean up for a leak free seal replace them likewise with the seats. If they don’t clean up the seats will need to be machined. As for the head gasket being copper it can be reused if necessary.
90cummins

 

[shanana]

After relapping the valves and double check them with break cleaner, the engine still does not start. Next step is to check the pistonrings. I didnt wanted to tear the engine apart but i have no other joice i guess

 

[ponytug]

@shanana I have to say that I am a bit puzzled by an engine with two hours, with great injector spray not starting, but 16bar is more than a little off. How did you measure that value?

When you turn the engine over by hand with the valve cover off, do you see the valves operating? Can you feel the compression? If you can, have you tried adding a few mls of oil into the cylinder and then trying to start it?

Welcome to TBN. Where are you located?

All the best,

Peter