I have an Roadster 1984 w/ about 66k adult driven miles, for quite sometime I experienced fouling of the spark plugs due to (I thought) a very rich mixture. Did a rebuilt of the carb at the Harley dealer (problem continued) and I was thinking of doing a valve's job or get rid of the bike altogether. Luckily I took it to a friend's shop (Old School Customs, Miami FL) and the mechanic after inspecting plugs, pipes (no smoke) and doing some testing came to the conclusion that I had a faulty ignition module, long story short it was replaced w/ a Compu-Fire system and apparently that' s the solution. I had not a very rich mixture but an incomplete combustion due to the improper functioning of the module. I'm Happy!
Don't work on the carb for an electrical problem! :^)
And that sounds like experience talking there!
:SM:
Hey we've all BTDT, right? Sometimes there's that subtle line between fuel and spark, could be either one and it comes down to process of elimination.
Just for sake of discussion, if the thing is running OK, just not 100% tip top, how do you diagnose weak spark?
-JW
:agree: not on any carb'd bike.
when I moved here, trailered the Sporty - ran great before, once unloaded it started to miss, run shitty, had a local shop (within walking distance) look at it, they work on lawn mowers, ATV's - metric bikes...etc :banghead:
they said they adjusted the carb on my 93 Sporty, :scratch: no sure what they did, it ran ok, but not perfect. Once I moved into my house I checked all the wiring one day and found a broken wire that came loose from the neg battery terminal, re connected and the bike ran great again.