Model 40 compression?

[WilsonDc]

What is acceptable compression? I have a model 40 U and currently the cylinders are running at 80 lbs. each.
I can't find the specs on this item.

 

[deeretails]

Most would be happy with that much compression-

 

[a49deere]

A "fresh" 40 should have between 110-130 psi

 

[J.Wondergem]

What is acceptable compression? I have a model 40 U and currently the cylinders are running at 80 lbs. each.
I can't find the specs on this item.

Was the throttle open or closed while you checked?

 

[WilsonDc]

It was six or seven years ago when I tested it. So I can't recall. Most likely the throttle was in a idle position.

 

[dan_41jdh]

Here's what Field Service Bulletin No. 236 shows...

 

[WilsonDc]

Thanks for the info.

 

[MikeinKy]

I recently checked mine and it was 125 on both cylinders

 

[WilsonDc]

Looks like thats about perfect.

 

[J.Wondergem]

It was six or seven years ago when I tested it. So I can't recall. Most likely the throttle was in a idle position.

Needs to be wide open..

 

[Jim.ME]

Throttle wide open, all plugs out, and battery able to maintain the same cranking speed throughout the testing, assist if needed. You should be cranking the same number of compression strokes on each cylinder (usually 5 or 6 to reach the point the gauge stops climbing.).

Is this a running engine currently or one that has been setting for several months or more?