Checking cylinder pressure

[JDJACK]

I how do I check the cylinder pressure on a hand start JD?
I was thinking about installing a compressor gauge and pulling the tractor with another tractor.
Anybody have any ideas.

 

[Anonymous-0]

yes, that would work pulling it...unless you feel man enough to start it with the compression tester side petcock open, then close it once its running. i have done this, but cranked on it a while before i got the timing just right. good luck either way. how much compression ya runnin?..ours was around 140 and i could start it by hand on 1 cyl.

 

[JDJACK]

I don't know that why I want to do it.
Will it run good enough on one cylinder to check it?

 

[Anonymous-0]

yes..it will..just crack the throttle wide open a couple times to get an accurate reading. have done this a few times.

 

[BushogPapa]

Here is a good question...

How much is the compression tester reading changed between testing with the engine Cold, and testing with it fully hot..?
There should be some difference, I would think..

Anyone..??

Ron.

 

[Anonymous-0]

Heck yea there is a difference. We have a JD A with power block, 8 1/2 inch stroke, and a heisler head. when we built the original motor, we added an inch spacer plate between the block and the engine frame so that the pistons would clear. after checkin compression, we had 115psi on the right hand cylinder and a 125 on the left hand cylinder. after taking 3 thousandths off of the spacer plate, we lost compression (although we hadnt actually ran the engine yet, we were just checkin by rolling the starter). an accurate reading should only be takin after the engine has run for a while and broken in.