electric tacho

hey guys is it possible to used a electric tacho with a pick up off the one of the coils for the tacho ? since its a 4 wouldnt normal a aftermarket tacho from a car work ?
cheers brenton

 

Should work... I don't see why not. Building a street fighter?

Off topic, I seem to remember it being odd on a harley though... something about it firing on the waste stroke and getting double counted in the rpms.

 

hmm well if it gettin double counter than u could set the tacho to 8cyl ?
not really sure how the bike will turnout but ill put up some pics when im done :lol:

 

No, any four stroke engine, no matter how many cylinders, fires every cylinder in two crankshaft revolutions. If it could be set to "two stroke" I guess it would work.

 

so what do u recomend for a tacho then if i dont use a cable driven one ?

 

Electric Tach

Various Tachometers

You'd need something like these. Notice how it says "no single fire systems". That means it's designed to work with an ignition system that fires its plugs on both the power and exhaust strokes. A single fire system fires only on the power stroke. Apparently, Honda V-fours use this system. Another tidbit of motorcycle trivia to store away in the grey matter...

 

Most bikes fire on the waste stroke? Didn't know that - I thought harley was just being lazy on the scavange... who knew? Not I.

 

In order for a cylinder to fire only on the power stroke, you need a single coil for each cylinder -or- a coil with multiple outputs that are fired indepentantly using separate pickups to the ignitor, and onto the appropriate winding on the coil. It's simpler just to use two coils and two pickups and fire on both the power stroke and the waste stroke. But then Honda had to be different....

 

Thanks - yes - as you say honda always likes to be different... some love them others hate them. Perfect vs Soulless...