shovelhead

[ezeriderr]

have a 83 flhtc shovel...problem is i have loss of spark sometimes.parked the bike after a hr ride,went to restart and no spark...had power to breakers,coil etc so i threw back in the old plugs i had in my tool bag and they sparked so went on my way.happened again a week later,parked bike and went to restart and no spark.changed plugs back to the spare set which didnt spark last time and they worked this time ...then yesterday driving down hwy i lost spark while riding,stoped turned off and on ignition and she restarted,...what causes a plug to work then not work then work again???is there a coil check i can do or possibly the module?looked at wiring and found no breaks or cracking in the ignigton system,i use champion plugs.
any help would be appreachited thanks
eze

[wfolarry]

I'd get rid of the Champions & put in a set of Autolites. Champions foul out to easily. Did this on a regular basis 30 years ago.

[ezeriderr]

i tried ngk but didnt last more then a day then did the no spark thing on me too...didnt mention the plugs that didnt spark on my bike i tested on another shovell and they sparked fine,tried back on mine and had week spark arcing off the end and not in the gap.also i run a stock coil and module

[wfolarry]

A bad coil can quit working when hot & start working again when it cools off.
Where the spark jumps the gap doesn't matter as long as it jumps!
Is it electronic or points?

[ezeriderr]

electric module in the bike.
when she died while riding it started right back up by time i coasted to side of road,and the other 2 times it had sat for a hour after maybe a 30- 1 hr ride so coil had lots of time to cool if hot.it wouldent spark with the plugs in it untill i put in old used ones which would spark right away.then days later the plugs that didnt spark would spark.seems like something is killing the plugs,overloading them maybe?...

[wfolarry]

Probably the module.

[vindex1963]

Originally Posted by wfolarry

Probably the module.

Yep, my '79 went through quite a few of them. Some would just quit and some would work, stop, work.

[ezeriderr]

im thinking module too....can anyone recomend a better one then the stock one which may or may not work all that long?screaming eagle or???

[ezeriderr]

wasent the module...its a short in my insterments dash.the pink wire from coil goes to tach...and a few other things on the dash didnt work properlly so i ran it for years unpluged,and not untill a few weeks ago when i pluged it back in thinking i had fixed the other shorting issues...was draining battery befor.so i loose spark intermetanly because of it.the bike still has stock wireing harfness and is reltivlly unbutchered and good condt.but the dash allways gave me troubles ,must be cause most the markings on the dash unit are in chineese...wtf

[Hillside]

Have seen tachs raise hell like that before.