In a traditional upright inline engine (i.e. 4 or 6 cylinder found in any watercooled car) can overfilling the oil reduce or limit engine RPM by touching the bottom of the bores of the cylinders?

I have a 1 liter 3 cylinder Kubota diesel. Book says 4 quarts and that's what I put in. After running for 15 minutes to warm up, it won't rev beyone 1/3 RPM potential.

Dipstick shows almost 1" over "high" presumeably after the oil filter has done its thing and purged air.

I'm just guessing, but the oil level may be as high as the bottom of the bores.

Yes, I can drain oil to the mark and restart, but I want an arsenal of other possibilities so I bring the right tools out with me.

the crank is NOT supposed to SWIM in the oil

'windage loss' i believe is the term....

nope.. I was barking up the wrong tree... drained oil down to the correct mark and it made no difference.

Either my tachometer is not correct, or this engine is "pegged" at 1500RPM (small diesel). Power curve shows a redline of 3200.

I hear terrible clatter above 1100 RPM so me thinks valve adjustment is next in pecking order. What else limits a diesel's RPM.... fuel flow?

This is a brand new Kubota diesel I just fired off for the first time, so I am not familiar with it.

I know I should take this question off to a diesel engine forum somewhere...

It's still an air pump. Check intake and exhaust. Shop rag in intake?