Hello
Pay attn to following symptoms
a) Long starting needed (on CNG) in the morning. More than 3 Selfs.
b) After starting on CNG (cold engine) it will turn off if you dont step hard on the accelerator.
c) When running up hills (either petrol or cng) you will experience lack of power (torque)
d) ALso unbalanced engne sound comes if more than 30% tappets are either jamed or need adjustments.
Regds