Compression Rate on a Low Compression W4 Tractor

[Jake96]

[i:080010e29d]Just enquiring about what the normal compression Rate is on a low compression model McCormick Deering W4 tractor. Petrol engine.
[/i:080010e29d]

 

[used red MN]

According to TractorData.com it looks like 4.75 to 1, realizing their data is not always 100 percent
accurate. If your asking how that translates to a psi or bar for a compression test I can?t help you.
If it were me testing it I would look for at least 50-70psi. See tractor data link.
mccormick deering w 4

 

[BarnyardEngineering]

Hopefully you've got a gauge that reads both bars and PSI. Seeing as you said "petrol" I don't expect you're in the United States...

75PSI is about the minimum for an engine to start with the starter and have a usable amount of power. Much below that and starting gets difficult.

A fresh engine will produce 125PSI or higher.