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IBR# 366
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Nice, Ken - thanks for sharing

-Brian
 

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IBR# 366
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Some 4-stroke engines actually do spark on every revolution, but the "off" sparks have no effect.

I don't think that the Boxer does that, but it does happen in some engines.
 

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meese said:
Some 4-stroke engines actually do spark on every revolution, but the "off" sparks have no effect..
The reason that Harleys sound like they do is because they also spark on every revolution (also known as the overlap stroke). If you made a Harley only spark on the compression stroke it would sound like all of the other V-Twins.
 

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Can't get it to download. See attachment
 

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XMagnaRider said:
Pretty cool, but the sparks seem to happen on every cycle, rather than every other cycle.

Is the boxer a two-stroke? ;)
Just about every vehicle I have had in the past few decades sparks on every stroke. Ignition firing on only power strokes pretty much went out when distributors did. If your vehicle (car, motorcycle, truck) does not have a distributor, then it likely fires on every stroke. The LT did, my BMW cars and Toyota Tundra truck do. I don't know about the Boxers, but assuming they are electronic ignition with no distributor, then they probably fire every stroke too.

There is nothing to ignite at the end of the exhaust stroke, so there was little reason to add complexity to the ignition system to not fire the plugs then. Made life a lot easier for the designers, and cheaper to manufacture the ignition systems.
 

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XMagnaRider said:
Pretty cool, but the sparks seem to happen on every cycle, rather than every other cycle.

Is the boxer a two-stroke? ;)
You didn't read the top of the page, did you?

"Flat Twin (Boxer): The famous motorcycle engine used by BMW since
1921/1922. Famously used in bikes like the R90S and R100. Note the 'Wasted Spark'."
 
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