I have a fx921 34 H.P Kawasaki engine that wants to run on one cylinder. If you pull the choke out about half way it runs better but not great. If I pull a plug wire off on one side it fires on the other so the coils are fine. It has a slight back fire through the carb. I did a compression check and get 120 and 90 on the other. The exmark dealer told me that 90 psi on one cylinder can be normal and that you can get a reading like this sometimes and that it is fine but I'm thinking he may be wrong as I have never had a good engine test that way. It doesn't smoke and I did remove the heads and have them checked and also replaced with new head gaskets and it runs the same. The carb is also clean and working properly. Any ideas as to what I should check or is it time to pull the 90 psi side out to see if i may have a ring problem as I suspect. Any input would be helpful. Thanks!