A cylinder with weak compression will change the way the cylinders fire.  A weak cylinder will have late firing time and a weaker explosion in the cylinder.  This will equate to lack of power and the dreaded “Excessive Fuel Consumption”.

Valves that are too tight do not close completely.  This will have two effects.  The first is carbon build up around the valve seat and face, which further interferes with the valves closing properly.  The second is burnt valves.  You will be able to determine that this has happened by the popping sound that comes out of the exhaust or intake.

The engine manufacturers have spent millions of dollars determining how to get the longest life out of your engine through proper maintenance.  Do yourself a favor and follow the maintenance schedule.  Like the old commercial said “You can pay me now or pay me later.”