How many pulses per revolutions for 4 stroke agility?

[MN_Scoot]

I just bought a cheap tach to adjust my idle speed. It says to first calibrate the tach for your motorcycle (how many pulses per revolution). In the directions, it says "most offroad motorcycles use 1pulse per 1 revolution and that motos with lighting systems typically have ignitions that send 2 pulses per revolution.

Wouldn't a 4 stroke Agility send 1 pulse per 2 revolutions (i.e. 1 spark during combustion stroke)?

Thanks in advance.

[zombie]

Thats a very good question... I never really thought about it.
Psychically it has to be triggered twice per Rev. The flywheel has to pass the trigger at TDC. Whether or not it fires twice is up to the CDI programing. Because of emission standards in place since before these scoots were even thought of I am going to go ahead, and assume they fire twice to help burn the unburnt fuel from incomplete combustion.

If I am wrong your tach will only read 1/2 the actual RPM's

[MN_Scoot]

Finally got out and did the tuning. The Agility is 1 pulse per 1 revolution.

[Stig / Major Tom]

Finally got out and did the tuning. The Agility is 1 pulse per 1 revolution.

Yep, I put one on my LIKE - and for a few days thought my idle was 900RPM...till I looked at a manual which said the idle speed was 1800, +/-100. Reset it and now I'm good to go.

[zombie]

Good info.
In thinking back the flywheel has a bump out or trigger. It can only fire once per rev of the crank but is one crank rev a complete fire/exhaust cycle on a 4 stroke?
I'm working on a friends bike later today, and I'll post that up.

[MN_Scoot]

Good info.
In thinking back the flywheel has a bump out or trigger. It can only fire once per rev of the crank but is one crank rev a complete fire/exhaust cycle on a 4 stroke?
I'm working on a friends bike later today, and I'll post that up.

This confused me too, but no, it just has one "wasted" spark in the 4 stroke process.

[zombie]

I forgot to check it out so Thanks for posting that up.
So it is TWO revolutions per fire - exhaust cycle but one trigger per revolution.

OWW! stroking out here...