Originally Posted by roycruse
Excuse my ignorance - I'm just curious - how does a faulty spark plug and therefore a non firing cylinder result in piston failure.
By my reckoning unless the fuel supply is interrupted there is still fuel and therefore lubricating oil getting into the piston - the fact it is not burning up surely would equate to more lubrication not less.
Or possible could it fail if enough liquid fuel built up in a cylinder that the increased compression its self broke the con rod ?????
Please can a mechanic explain
I am puzzled about this too but am inexperienced with 2 stroke behaviour under these conditons.
In a 4 stroke, the non working piston would be a "passenger" but would not essentially be in immediate risk of failure. I have done many racing laps in a high horsepower "V7" without drama in the past.
I have spoken to the guy who lost his Etec 250 they are now citing "injector failure" as a reason.
Now this also resulted in the destruction of one bore and he said it happened instantaneously - no warning, but it caused the entire motor to shut down as a result. This sympton is worryingly close to the spark plug failure in one piston/bore as mentioned in the start of this thread (basically both instances reflect the failure of ignition in one cylinder through spark or fuel.)
I am trying to get hold of the dealers actual tech report and I will post it here for all to see, not for negative reasons but to perhaps help put people's mind at rest or on alert as I know several people about to part with their hard earned.