Spark Plug Gap

[Tom Ludolff]

Can anyone tell me how spark plug gap would affect performance??? Anybody ever done any experimenting???

Tom L.

 

[Tom Ludolff]

Anybody have anything to offer? I'm sure if there is no gap at all, the bike won't run. So it has to have an effect. I think the spec. is .028 - .032. Maybe some bikes will run better at .028, while others run better at .032? Has anyone tried different gaps?

 

[Michelle]

I take mine out the box, put it in a plug holder & replace the old one when necessary. Never gapped one.
Henk had an old KTM & had to meticulously gap it, any further apart or closer the bike wouldn't run (or if it would, not for long). Then again, the bike died with ignition problems (since given to a friend, well, he was, not sure he still is after that) hehehe
Not much help sorry, but you gotta reply lol :)

 

[MX175]

Though I do not have data to support it, my opinion is that you will never feel a difference in performance by changing the plug gap. Maybe there is a little effect, but it may only be detectable on a dynometer. The gap is to optimize the spark and the plug longevity/reliability.
Set the gap, put it in, and forget it. Then work on your jetting if you need to optimize performance.

 

[Braahp]

Gap actually can make a difference in temp, performance, etc. Combustion begins at the positive electrode of the spark plug. It is very important to select the correct plug for any given application because if neglected, performance suffers. Maladjustment of spark plug gap as little as 0.002" can cause a loss of mph! Why? Because the gap between electrodes controls combustion temperature to some extent and if your ignition is weak to begin with, combustion will not occur as it should. This causes loss of power. But you have to be pretty darn anal to even mess with it. The trick is to run as large a gap as possible that your particular ignition will fire. If you want to get real tricky try indexing your plugs. Good for another 40-50 rpm or so if done right. Indexing is using a thin washer to achieve the open end of plug (when torqued down) electrode facing towards exhaust port.