R ruicunha Member Oct 24, 2021 #1 Tried searching on internet and i cant find the answear for gx390 psi stock compression value. anyone knows? Thanks.
Tried searching on internet and i cant find the answear for gx390 psi stock compression value. anyone knows? Thanks.
MO Predator Racer Member Oct 24, 2021 #2 8.2 : 1 Is compression ratio Don't quote me on this but I remember seeing around 85-100 psi is good compression for them on the internet. If it is a worn motor I think I have heard around 70psi
8.2 : 1 Is compression ratio Don't quote me on this but I remember seeing around 85-100 psi is good compression for them on the internet. If it is a worn motor I think I have heard around 70psi
9 95 shaw Site Supporter Oct 24, 2021 #3 Compression will depend on cranking speed, and valve lash, if the compression release is still installed and functional. A leak down test is more representative of engine condition.
Compression will depend on cranking speed, and valve lash, if the compression release is still installed and functional. A leak down test is more representative of engine condition.
flattop1 Dawg 89 Oct 24, 2021 #4 They pull fairly hard even when stock . It was a two hand pull for me .