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Main Area => General GS500 Discussion => Topic started by: Garethbourne on November 10, 2007, 03:17:12 PM

Title: PPR (how many pulses per revolotion from the coil)
Post by: Garethbourne on November 10, 2007, 03:17:12 PM
Hi, i am fitting an electronic RPM gauge to the suzuki and i need to find out how many times per revolotion the coil pulses, can any one help ?
Title: Re: PPR (how many pulses per revolotion from the coil)
Post by: mach1 on November 10, 2007, 03:21:57 PM
pull the plug wire and count how many times it shocks you. :laugh:J/K. I'll let someone else take this one
Title: Re: PPR (how many pulses per revolotion from the coil)
Post by: Garethbourne on November 10, 2007, 03:36:00 PM
Quote from: mach1 on November 10, 2007, 03:21:57 PM
pull the plug wire and count how many times it shocks you. :laugh:J/K. I'll let someone else take this one

Hey, thanx for the tip, dude, but i think i will give that one a miss, for now, and try to find a les painfl way of finding the information, lol.
Title: Re: PPR (how many pulses per revolotion from the coil)
Post by: mach1 on November 10, 2007, 03:58:57 PM
you can also get a spark tester from an autoparts store some go between the plug and wire other go into the wire and you just clip the otherside to a ground and your able to see the spark and can count how many times it sparks/pulses. 1 cycle= 4 revs intake,compression,power,exhast you have one power stroke which is the spark plugs getting a pulse from the coil so wouldnt that make it 1 pulse her cycle, If you are trying to figure out how many per min than if your at 1k thats 1000 rpms break that down to groups of four and thats your number of pulses per min at 1k.
Title: Re: PPR (how many pulses per revolotion from the coil)
Post by: dgyver on November 10, 2007, 04:57:15 PM
What kind of gauge is it?

I have installed plenty of gauges and just used the black/yellow wire on the right coil for the signal.
Title: Re: PPR (how many pulses per revolotion from the coil)
Post by: Kerry on November 10, 2007, 05:41:05 PM
Quote from: mach1 on November 10, 2007, 03:58:57 PM
1 cycle= 4 revs intake,compression,power,exhast you have one power stroke which is the spark plugs getting a pulse from the coil so wouldnt that make it 1 pulse her cycle

Uhhh ... don't all 4 cycles occur in 2 revs of the crankshaft?

    1st rev = down & up = intake & compression
    2nd rev = down & up = combustion & exhaust

That would work out to 1 pulse (per cylinder) for every 2 revolutions of the engine, right?

Having said that, I remember reading that the GS fires its plugs every time the piston hits the top of its stroke.  In other words - between the compression and combustion strokes and then also between the exhaust and intake strokes.

If that's true, then it works out to 1 pulse (per cylinder) for EVERY revolution of the engine.

Anyone care to confirm this rumor? (http://bbburma.net/Smilies/dunno_black.gif)
Title: Re: PPR (how many pulses per revolotion from the coil)
Post by: mach1 on November 10, 2007, 06:30:02 PM
my bad kerry you are correct. 1 rev is two strokes I must be tired.
Title: Re: PPR (how many pulses per revolotion from the coil)
Post by: GeeP on November 10, 2007, 09:32:58 PM
Quote from: Kerry on November 10, 2007, 05:41:05 PM

Uhhh ... don't all 4 cycles occur in 2 revs of the crankshaft?

    1st rev = down & up = intake & compression
    2nd rev = down & up = combustion & exhaust

That would work out to 1 pulse (per cylinder) for every 2 revolutions of the engine, right?

Having said that, I remember reading that the GS fires its plugs every time the piston hits the top of its stroke.  In other words - between the compression and combustion strokes and then also between the exhaust and intake strokes.

If that's true, then it works out to 1 pulse (per cylinder) for EVERY revolution of the engine.

Anyone care to confirm this rumor? (http://bbburma.net/Smilies/dunno_black.gif)

Yep, the GS has a lost spark ignition. 

It sparks at the same position BTDC every revolution.  The ignition rotor has no provision for determining whether the engine is at X degrees before TDC on the compression stroke or the exhaust stroke.
Title: Re: PPR (how many pulses per revolotion from the coil)
Post by: Garethbourne on November 11, 2007, 01:42:01 AM
Thanx Geep, thats the information i was looking for, i was'nt sure if the susuki had a spark on it's exhaust stroke or not, usualy , as kerry pointed out, the 4 stroke cycle only as a spark on the ignition stroke, and i have the rpm gauge set to 0.5 ppr, so looks like i need to set it at 1.0 ppr. well i think that should work out, lol, if not i gues i will have to ook at it again, thanx.
Gareth Bourne