Here's a total slam-down stumper.
This'll drive ya nutz, Fred.
1995 Tomos Targa TTLX - 21,550+ Miles (stop laughin, it's true!)
For no apparent reason, simply begins to have extreme difficulty starting, and problems with the engine just dying without apparent cause.
Problem originally seemed clogged exhaust, cleaned and replaced exhaust, removed baffle to prevent recurrance of problem.
Damn thing still didn't start, or would, then wouldn't...and still dies for no apparent cause.
Checked ignition coil (CDI Style) - readings intermittent, sometimes enough juice, sometimes not...always SOME, but usually not enough to fire the plug.
Checked Voltage regulator - perfect.
Checked Kill switch for short - none.
Checked wiring for continuity - perfect.
Checked CDI timing (old method, which is somewhat estimated, yes) - it appears to be dead-on.
Checked plug, tried with...Bosch W7BC, Bosch W8AC, NGK B6HS, NGK BP5HS, Champion L86, again...firing was completely intermittent, save for the W7BC, which would hardly, if ever - fire.
(mind, the manual that came with THIS targa called for a W8BC, which is not at all the correct plug, and the W7's were all that could be found locally.)
Ordered coil from MopedJunkyard...order changed without customer authorisation to an italian part which when hooked up, failed utterly to function...whatsoever.
(Shipper stated wrong part was ordered, and chose to substitute supposedly "correct" part for a 95 Targa...which it is certainly not.)
Checked generator function after testing and getting reading of no-voltage with new "supposedly" correct part - generator putting out 12v,80w - perfect.
Checked cable from coil to plug - full continuity.
Check plug cap, loose, corrosion...cleaned and repaired, no appreciable effect either way.
Ordered the correct part from a forum member, which did work as it came off a working moped, installed.
Vehicle nearly starts...I can HEAR it trying to catch..but does not.
It did start one time, ran..but would not start after that.
After several good kicks, the back pressure increases (you can feel it on the pedals) , and it will produce a small backfire....but will not start.
Carb removed, cleaned, replaced - no appreciable effect.
Exhaust again removed, cleaned, replaced - no appreciable effect.
Exhaust port at lower cylinder cleaned - no appreciable effect.
Compression checked - compression solid, no leakage.
Fuel flow checked - working perfectly.
Airflow checked - no obstructions.
No way to check the mixture in this case, but it ran quite well previously and is running a #51 Jet.
Anyone wanna tell me what the bloody hell could possibly be WRONG with this damn thing ???
Fred, you saw the onset of the problem yourself, any ideas ?
Cause this is drivin me BONKERS!