I have a softail chopper with a 2000 Evo engine, low mileage, S&S Super E carb, and straight pipes. I’m having what I believe is an electrical issue. The bike starts easily, and when I gently roll on the throttle, it usually responds as it should. But when I give it a quick twist of the throttle, it cuts out. I originally thought it was a fuel issue, but I’ve checked that entire system, rebuilt the accelerator pump, and that doesn’t seem to be the problem.

When I switch it on before starting, the speedometer light flickers. When I’m riding, the headlight surges as I rev the engine. I’ve checked the battery, battery connections, and other wiring to ensure I don’t have a short. The bike is very low mileage, and the Dyna S ignition is very new. Can anyone give me some things to check? Thanks in advance for you help.

 

It could be a possable charging issue, or a connection problem like battery connections and grounds. Thats where I would start

 

do you have a kill switch, maybe wire being pulled and shorted, strap on a cheap volt meter and see

 

Sounds like a loose wire to me too. Maybe a ground.

 

You may have a regulator prob. (could be alt but sounds like reg). Also you still have a carg prob. sounds like a vac leak! that is JMHO

 

You may just be twisting to fast. Even my honda didn't like it when I did that.

 

I don't know about an electrical problem but it sounds like you could have a problem with old or weak spark plugs.

Any time you throw a heavy load of fuel into the cylinders you raise the compression pressure on the spark plugs. When you give it a fast twist of the throttle, you are throwing in a lot of fuel all at one time thus raising the pressure on the plugs. As soon as the cylinders go through a couple of cycles of the engine, the fuel load is cleared, the pressure goes down and the spark plugs begin to fire again and away you go. Does this sound like your symtoms?

I have seen this same problem in car engines over the years.

Being as you can roll on the throttle normally and you do not have this problem, it tells me the plugs could be bad.

 

anymore ideas, guys?

 

Same thing happened to me , turned out to be the regulator, one sue sign is the bike runs slightly rough,

Reddog
Manchester UK