Why's the W5019 Compression So Low?

[daltotron]

Ok, so I'm trying to revive my dad’s old W5019 mower, but I'm running into a bit of a trouble with the compression. The mechanic gave the valves a good clean and did a leak down test, and that looked solid. But when I ran the compression test, it only showed 20-25 psi—yikes!

What’s the normal compression supposed to be for this engine? Any ideas?

 

[M0Cena]

I don't know much about that engine, but try adjusting the valves to see if that helps. You should get a reading of 100psi without the decompressor.