Spark plug gap settings

[caveman]

     Hey Guys,  Always wishing you the best of days, 

      First  - - -  I wish to express my thanks to all of you to have this site where questions of so many topics concerning small engines and the "Builds" that carry us.    My nearest neighbor being 1/4 mile from me  - - --  THIS site is Soooo important to me .

      When in town  [17 miles away]  I asked the man in the auto parts store about the plug gap setting  for my ATV  [ thought 35" as for my car]   but without any hesitation he said that was too much and stated 28" .            My question is why the difference and what is best for an  ATV  engine of 250cc     and for my mowers  :  5 hp /  13 hp /  17 hp ?      Is the power affected  ?   Is the starting affected ?  Is there something  I've  overlooked  ?

      Thanks again for your thoughts and for your help.   caveman   [Norman]

[money89tractors]

On these small engines (and all engines for that matter, just smaller ones more) , the plug gap can be used to change timing by a degree or 2. If the factory plug gap is 25 for example, and you set the gap at 30, you may have retarded the timing by 1 or 2 degrees. This in turn could make the engine run better or worst. This works the same way is you set the gap to 20 , you may have advanced the timing by a degree or 2.

The cause of this is the time it takes for the electrical charge to "fire" the gap. The wider the gap, the more energy and time (long distance to travel) to make the plug fire.

Hope this helps.

-Phil

[caveman]

      Hey Phil,   Here's wishing that your day goes well for you,

            Sure do appreciate the info about the spark plug settings.    As much as I've worked on cars - - -  I just set the plugs and didn't even understand the impact the settings had on the engine timing.    Never gave it a thought.    I'm always learning.   [ You know my age]          

            Thanks again Phil  - - - -  You GUYS are really something.           caveman  [Norman]