My cousin has a Kohler twin cylinder CH22S that started running badly. A compression test showed 180psi in one cylinder, 30psi the other. Thinking a blown a head gasket, he pulled the 30psi valve cover and found a bent exh push rod and the intake push rod laying loose. Together he and I can't figure why. One would think the exh valve hit the piston (bent push rod) but there are NO MARKS/DAMAGE whatsoever to neither the valve or piston. On to the intake; the rocker arm bolt was good/tight so what would cause that push rod to just "fall out" of place? The lifter has a bad check valve? I'm thinking it collapsed even if just for a second or so. Seems odd to have TWO push rod issues on the same small engine, but on the same cylinder! Until this the motor ran great, started easily, no smoke, no knocking, no noises at all then out of nowhere this. Other then the valve/piston hitting, I can't see what else could/would bend the push rod. I've worked on small engines on-off for many yrs so the repairs are no problem but have no ideas of what the heck happened. :confused2: