HarleyTechTalk

Technical Forums => Shovel Head => Topic started by: tuff luck on November 11, 2008, 10:43:17 AM

Title: Backfiring and no charge condition
Post by: tuff luck on November 11, 2008, 10:43:17 AM
Have a 1981 Shovel stock with stock ignition (electronic) The battery does not charge, the stator checks out fine. The motor backfires out the carb and pipes even when the battery is fully charged. The battery load test fine. Can a regulator cause a backfire situation, even when the battery is fully charged? There could be two problems here. Thanks in advance!! Have tried running separate ground wires to make sure it is grounding.


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Title: Re: Backfiring and no charge condition
Post by: NormL on November 11, 2008, 11:09:49 AM
Yes, low voltage can cause backfire. 
battery checks out good with hygrometer or load tester?
It it's a good battery does the reg put out 14 v dc to the battery when running off idle (2,000 rpm)?
Title: Re: Backfiring and no charge condition
Post by: tuff luck on November 11, 2008, 11:45:50 AM
We use a battery load tester made for motorcycle batteries, and  the voltage when running is not the usual 13 to 14 volts usually around 12.5 volts.

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Title: Re: Backfiring and no charge condition
Post by: Lew on November 11, 2008, 11:52:40 AM
If the battery checks out.  Possibly a short in the wiring or a switch.  That could have taken out the regulator too.  I'd have a look at the wiring and check the ignition switch, coil/s, and the handlebar switch too.  Have a look under the dash cover for something touching first.  Very common for the cover to touch one of the terminals on the ignition switch.  Check under the seat fo a possible pinched wire there also.  Good luck.
Lew
Title: Re: Backfiring and no charge condition
Post by: D3bikes on November 12, 2008, 01:21:59 PM
if the battery isn't charging and the stator checks out, then you either need a regulator or the regulator ground is not good.  Also check for a shorted out coil wire or cracked or bad coil.  Sometimes the ignition module is to blame.  I can't remember if that year had the sensor cup or weights behind the sensor plate under the timer cover, there could be some issues there too. Also check for shorts at the kill switch  on the handlebar