New Tecumseh engines should have a compression reading of at least 80 psi. If your reading is at least 60 psi (or the specification found in your engine manual), then compression is acceptable.

What is normal compression for small engine?

Most small engines require at least 90 pounds per square inch (PSI) of compression when hot, and 100 PSI when cold. If air is leaking somewhere in the engine, you will notice a drop in compression.

What number is good compression?

So, as a general rule a compression of 135 PSI or better, is excellent. On the other hand, a compression of 85 PSI or lower, is extremely bad. Firstly, the most desirable situation is that all cylinders, give the same or close to the same reading. In addition, that reading should be, above 135 PSI.