Those numbers look nice to me. But let's see how it does with the leakdown

 

Getting ready to do the leak down test and I recorded the video below of me rotating the crankshaft. At some point during the rotation you can hear a noise and I lose pretty much all resistance on the crankshaft bolt, it sort of clicks again and then it regains tension. Is this normal?

 

Did not hear or see anything untoward.

I'm unsure how you are going to avoid pulling the motor out of the frame and pulling it apart to see WTF is going on, provided that you are convinced the oil cooler setup has nothing to do with the cooling system leak (and I'm not convinced that you've ruled that out). The only thing left beyond that is a ruptured coolant passage.

 

I ran the leak down test and could hear air escaping from the cylinder head area and the right side crankcase from all four cylinders. Sounds like a tear down is in order.

 

Did you have each cylinder on the compression stroke?

I find it hard to believe that you have that much leak down with those compression numbers.

 

I believe so but wasn’t 100% sure. I followed the instructions in the service manual for checking valve clearances. First set the #1 cylinder at tdc and the manual states to check the intake valves on cylinder #1 & #3. “In” and “Ex” on the cam chain sprocket were even with the cylinder head and outboard on the cam chain sprockets. Camshaft lobes were opposed. Cylinder was definitely at the top of its stroke, just not sure of it was the compression stroke.

 

Mate I see the clutch cover is out and the clutch appears pretty dry which means oil has been drained and it's been some time? I hope you do realize the camshaft is being rotated without oil although there'd be some residual oil still left so it's not 100% dry. Re the lack of resistance, I did notice it as well when I did my valve clearances. I noticed that the crank offers very little resistance in through some angles of rotation and it's not a smooth rotational movement with the cam chain bulging and stretching somewhat. I interpreted it as natural vaccum resistance of the cylinders through various strokes. May be the experts can comment.
Best of luck in getting your steed back on the road-remember, you'll do it eventually, patience is the key

 

I removed the head today, pictures of the pistons and the intake/exhaust valves below. The head gasket was badly warped right between cylinder 2 & 3 where the oil cooler passage is. Pictures below.



Concave gasket warpage on the block
Warpage on the head gasket

 

Holy ****. I guess you found the problem. How does the head and block look under the gasket?

 

Indeed. Screw the gasket...how's the head and the cylinder tops?