MF, the filter mesh is normall on the other side to the metering diaphragm - above the needle valve.
Normally they will run spot on with just the metering diaphragm changed. I only keep 3 types - zama c1u, zama c1q and walbro. I really should get another c1q type with the breather hole in the middle, but I have only needed this once on a stihl
This (along with fuel lines and filter as required) will get 85-90% of engines running.
