Here it is... I have a 1988 softail custom with 69K on it. I recently changed the old Super B carb to a CV, rebuilt the top half of the motor, drag bars, performance jit for the carb. Now I have had a problem since last July of losing power when I'm riding. It has gotten to the point that I can't go more than a block or two wihtout the engine shutting down. I had no idea what it was until I had a Eureka moment and shut off the killswitch while riding. Voila! Same symptoms that I was experiencing on its own. Power drops, no response at the throttle and the lights dim, after a few seconds or sometimes minutes, it would backfire through the carb or pipes and take right off... only to do it again a few moments later. Last night I pulled the Wires back through the bars and nothing, no shorts, bare wires etc. Tracked the main wire off the positive side of the battery to the solenoid and found a bare spot right beneath the oil tank where it was rubbing on the engine. Tapped up and decided to test it out... and then it happened again. Any one else have this problem? Is there something that I am missing? Something that is common in these older bikes? Id really appreciate the input, I'm supposed to trade this thing in on Saturday for a 2010 Road Glide Custom, but would love to have one last ride without problems. Please help!

Replaced:
Carb
Petcock
Fuel lines
Iginition coil? (located in nosecone)
Internal parts of carb
Plugs

 

Hey, I have the same bike with the same problem, however, mine seems to happen on very hot days. I've replaced almost every electric part on the bike an it still happens from time to time. Have you found a fix ?

 

You might want to recheck your carb float. Sounds like it might be to low and shutting off the fuel.

 

Thanks Jim, but I've already replaced the stock carb with a mikuni and still have the problem. I can tell you that the aftermarket tach I installed goes haywire when this happens with the needle jumping back and forth erratically. That's what made me think electronics. I've even replaced the key switch, ignition coil, regulator, stator sensor, ignition module. Usually I have to pull over and let the engine rest for awhile, say 15-20 mins, then it starts right back up. If you've ever had a spark plug wire come loose and you loose a cylinder, that's how it runs when this happens. Oh yeah, I replaced the plugs and wires when I replaced the coil.

 

So next you should disconnect the tach...if it is shorting out it could be grounding your ignition.