Hooking up Manometer

[crazypj]

Cold and hot can tell you things about motor, just do cold with throttle open for now and see what you get.
I would expect numbers to go up by 80~90 psi with throttle open. Electric starter is ok to check compression, wasn't sure you still had it fitted

 

[Hot Rod Troy]

Now I have 125 on the left and 80 on the right, both WOT. Now I gained on the left and dropped on the right. Does that give any ideas?

 

[teazer]

PJ has you on the right track. At this stage you have determined that one side is rather low and the other side is really low.

It's possible that the valves have insufficient clearance but they may have burned if they have run like this for long. It's more likely to be a bore/piston problem. I'd do a leak down test next (after you check valve clearances) . I use a Tavia twin gauge leakdown tester, but really all you need is to apply compressed air to each plug hole in turn and listen for air leaks. If you hear air hissing out of an inlet of exhaust port (when the valves are closed, that valve is leaking. If you hear air hissing into the bottom of the motor, it's getting past the rings.

That will point you in the right direction as to where the problem lies.

 

[crazypj]

You have to set each cylinder at top dead center compression to do a leakdown test. (both valves closed, rod straight up and down so it doesn't turn crank)
If you have access to a compressor you can probably use the adapter you used for compression test.
If you did compression test correctly, and valve clearance's are correct, 80psi is low enough to pull motor apart, you have a serious problem somewhere, most likely exhaust valves burned?

 

[Hot Rod Troy]

I did a leak down on it before. Not sure if I was at TDC or not but I could hear air leaking out the bottom. I'll get hold of my buddy who has a leak down tester and we'll try it again. It looks like I'm gonna have a winer project.