No Spark for '77 Express

Fred Jurgensen /

I have replaced the plug, cleaned and reset the point gap, but still get no spark. What diagnostics can I do to determine what part or parts might be bad? How sensitive is the electrical system? I did have to cut the brake light wire on the right hand side. Could this have messed up the on/off switch?

Re: No Spark for '77 Express

had to cut a wire? Can you fill in the gaps and provide some recent history as to what you've been doing?

Re: No Spark for '77 Express

Fred Jurgensen /

The assembly where the brake cable went to the brake lever had broken. I took a brake lever assemble from another old motorcycle and attached to the handle bar, but had to cut the wire to make room for it. I have tried to get a spark by splicing the wires together and making sure they were not touching, but no luck either way.

Re: No Spark for '77 Express

so this bike is a new project.. it never had spark as far as you know?

manual / wiring diagram

"HERE":http://www.mopedriders.org/article_view.php?faq=2&fldAuto=52 is a manual for '77 express..

before suspecting bad components, go through the wiring, especially the kill switch and key/ignition wiring.. If either the ignition is "off" or the engine stop switch is "on" it grounds and kills the spark.

This wiring (page 27-1 in the manual) looks very similar to the Hobbit, except for the battery. It's fuzzy but i can make most of it out.

You should be able to just bypass all harness wiring and switches by connecting the black (white stripe?) wire coming out of the magneto directly to the condenser. Kicking it over should give a spark if all ignition components are functioning.

On the Hobbit the ignition coil and condenser are at the rear of the bike and it's see the condenser wire and hook it to the magnito ... If your condenser is inside the magneto, i don't know if it's gonna be easy or difficult.

Re: manual / wiring diagram

edit:

On the Hobbit the ignition coil and condenser are at the rear of the bike and it’s _easy_ to see the condenser wire and hook it to the magnito.

(my condenser wire is about 18 inches long and connects up to the middle of the wiring harness.. easy to play with it since the condenser is not inside the magnito.)

Re: No Spark for '77 Express

Fred Jurgensen /

No, actually, it did have spark and was even running ( although poorly). I had cleaned the carb. to try to resolve this and also re-gapped points etc. Then after re-assembly, I get no spark. I have made sure the ground wire is attached, but I don't know how to check the magneto etc.

Re: No Spark for '77 Express

i dunno what you mean by _I have made sure the ground wire is attached_

try connecting the condenser directly to the magneto ignition-coil / points as previously outlined..

Then remove the plug, re-attach it's boot and solidly ground the plug's base to the engine fins.. Kick it over and observe spark. Another way would be to use some Starter Fluid and a install a new plug (or one known to be good), bypassing possible carburation troubles while confirming ignition is ok..

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