T140E won't run correctly - HELP!!

 Hi

I recently acquired a 1980 T140E Bonnie. The bike was running when
purchased, but kept blowing the main fuse. I fitted a new wiring harness to
resolve the short circuit (at the frame near headstock), but although I have
managed to get the bike running long enough to get it out and have it MOT'd
it now refuses to start.

Symptoms would appear to indicate an ignition fault. When it was running OK
before it would misfire and not respond well to the throttle opening until
fully warmed up. Now it will only start occasionally on one cylinder. I
removed the plugs (newly fitted), but can only get a spark when they have
been thoroughly cleaned. Re-fit the plugs and it will try to start then go
dead again. On removal again - no spark!! I have fitted new ignition leads,
plug caps and spark plugs. Definitely getting 12 volts to the coil primary's
per shop manual testing procedure, but can't figure out why the plugs seem
to go dead immediately after refitting them.

Does anyone have any ideas that might help?




Many thanks ... Dave

 Dave Colville wrote:

Have you tried new plugs? If the old ones were fuel fouled, you'll have
a hard time ever getting it to run right on 'em.

Points or electronic ignition?

Running a battery or without?

Checked charging system output if running without?

What carb(s)?

Les

 one Idea I had a 68 Daytona that had the same problem turned out to be a
previous owner had over tightened the clamp holding the left coil slightly
crushing the case caused an intermitent short

primary's