Compression

[Randy K. Crump]

John Deere A 1951 model. What compression should it have? Should I have both plugs out when I check the compression?

 

[BushogPapa]

Yes, both plugs OUT and throttle opened..Spin with Starter...

Compression ratio listed is 5.6: 1 80% of that total is good..

 

[Randy K. Crump]

Can you provide what the compression should be in psi?

 

[BushogPapa]

14.7x5.6 will give you a very close answer..

 

[cornerpost]

Atmosphere is 15 plus psi. Six times would be 90 psi.

 

[66 Caprice]

The compression should be 110 psi----based on Mr. Thinkers Almanac