single fire problem! HELP PLEASE!!!!

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Aug 15, 2007 | 10:53 PM

dts

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Joined: Aug 2007

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single fire problem! HELP PLEASE!!!!

sorry about this but this is long story...THIS IS MY PROBLEM! I just spent week putting a 6 speed in my 91 fat boy,took out for a ride ran like hell thought it was geared to high but no its only running on 1 the front cylinder.had crane singlie fire in it for 10 years always ran great even as I pulled it into my garage to do the tranny! figured it had to be the coil changed that still no go .took it by this shop the dude tells me its my single fire is toast, I don't see how it can go sitting in garage but...maybe,I follow a thread on this site that says crane gives directions of using a test light grounding it and testing the ign.leads at the coil if its good the light will blink as the rotor fire the cylinder ,if its no good the light wont blink seems easy but when I touch the light pobed to the lead of the cylinder thas firingthe engine dies!!!! the tec from crane is baffeled as me,doesn't make sense he says.must have a short I have taken that damn bike apart looking for a short no luck .so today I got a new HI-4 crane single fire hooked it up to the tune of $400 plus fired it up and vollia the same damn thing I'm pullin the last of my hair out as I type this!!!!!!!!!
anyone got a answer,a thought a guess,anything my summer is shot if i don't get this figured out!!
HELP PLEAZZZZZZZE

Aug 16, 2007 | 06:08 AM

geargrinder

Road Master

Joined: Dec 2006

Posts: 1,058

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From: Omaha Nebraska

RE: single fire problem! HELP PLEASE!!!!

Hopefully someone more familiar with your 91's ignition system will jump in here but here are a few things to consider until then. On certain types of ignition systems that use a ballast type resistance in the +12Vto the plus side ofcoil,some low resistancetest lights will partially short thetrigger signalfor negative side of coil to groundstalling the engine, could be normal. So the way you want to use a test light is when cranking engineover with starter only, then it should dimlyblink on/off even though engine may not start, light should brightly blink on a non ballast type resistance system. Your test light shouldbe litwhen placed on the + side of coil with ignition switch/run switch on, should stay lit while cranking but may alternate from bright to dim while cranking if ballast type ignition. Wish I knew if your ignition system pickup was points, inductive, optical,hall affect or crank trigger system and if you have two negative inputs to coilso I could go further, but better stop here.

Be careful with test lights, some have such abright, low resistance bulb that they practically short out delicate (ignition)circuits, like using high input impedance multimeters myself.