Are there any spark plug mods worth doing? (ie indexing, side gapping, ect...)

Dustin Mustangs

Dustin Mustangs

uʍop ǝpıs dn
Location
Holland, MI
Has anyone tried any of these on a 701 based engine? Side gaping, plug indexing, running a gap out of spec, different heat range, ect... Any worthwhile gains to be had here or just a waste of time?? Also, on a two stroke, which way should the open side of the electrode point when indexing???
 
Waternut

Waternut

Customizing addict
Location
Macon, GA
I did a lot of searching and reading on this a couple years. It seems like a lot of this stuff produces measurable results when done just right for the right engine but none of them produce any results that would justify the cost.

Indexing the spark plugs can produce measurable results but not noticeable results. In addition, there is a debate in two stroke engines on which direction is the best to point the electrode. Apparently it varies from engine to engine and if they're both pointed the wrong way, it can produce measurable negative results. So based on this, I figured this mod wasn't necessary for me.

I tried side gapping as well. The spark looks a lot bigger and more powerful but this also didn't produce any noticeable results and you replace plugs a lot more often.

I run total loss so my spark energy is stronger. I run a little bigger gap than stock but, once again, no idea if I'm helping or hurting myself. My engine runs strong, my plugs look good, and my carb is tuned properly. I quit worrying about plugs.
 
#ZERO

#ZERO

Beach Bum
Location
Florida - U.S.A.
Indexing plugs is more for the 4-stroke engines with valves and wedge shaped combustion chambers IMO. You can gain some extra rpm if you grind the ground terminal rounded on the end to match the electrode diameter and experimenting with spark plug gap thickness will gain some extra rpm but you'll need a tachometer to notice the difference. Also the two stroke NGK racing plugs work well because they have a deep seated copper core with a wider heat range that's more resistant to fouling which use a fine-wire center electrode which provides better ignitability.

Resistor 2-Stroke Racing Plug
BR8EG-SOLID
#3992

Non-Resistor 2-Stroke Racing Plug
B8EG-SOLID
#3997
 
#ZERO

#ZERO

Beach Bum
Location
Florida - U.S.A.
Waternut said:
The racing plug looks incredibly similar to a side gapped plug.
Click to expand...

The side fire electrodes are used for long term mileage and the B8EG plugs use same ground electrode as the B8ES plugs. It's just the internal construction and center electrode material & diameter that are different otherwise they appear the same as the BR8ES or B8ES spark plugs.
 
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