Spark Plugs

[cwilliams]

When doing a valve adjustment, what about switching the plugs from main to bottom. They are the same part#.

[dirtrider]

Evening cwilliams

 

That really depends on what you are working on.

 

[cwilliams]

Working on a R12oort

[dirtrider]

Evening again cwilliams

 

 

 

Yes, they are the same primary & secondary.

[Skywagon]

That is a common practice on air cooled airplane engines. I move top to bottom every 100 hours or at the annual inspection. Don't ask me why, it is just how I was taught. I can tell you the plugs on top have less lead to clean and the plugs on bottom tend to show signs of running richer...

 

Not sure about a motorcycle, but guess it can't hurt.

[aggieengineer]

They're alternated to reverse the polarity, even the wear on the electrodes, and extract the maximum life out of a set of very expensive plugs.

[dirtrider]

They're alternated to reverse the polarity, even the wear on the electrodes, and extract the maximum life out of a set of very expensive plugs.

 

Morning aggieengineer

 

That won’t help on the 1200 hexheds as all 4 plugs spark in the same direction.

 

[aggieengineer]

That's okay. A standard plug for an aircraft engine is over $20, an iridium plug, a staggering $50....each! Automotive plugs are cheap by comparison.