At my wits end here! ive redone many scooters in the last 10+ years..but this is as frustrating as it gets. bought used off a guy who was basically going to scrap it, so i felt i did a good deed saving it! ill give a brief history...
helluva mess when i got it but it kinda ran, think guy was done with it as he couldnt get it to rev. bike has new charge coil, and ign coil. Carb and all cleaned and good to go. at one point outta the blue it revved up and ran great for about
2 mins, but as soon as the rpms dropped to idle, it wouldnt rev again.
Ive tried removing the control unit and running it, dissambled the "off start run" key switch and cleaned and lubed. hell at one point i had the whole key switch box on the bench and still nothing( thought maybe that would bypass everything and give it its full rpms) all wiring has been inspected as well.
The ONLY time it revved up is when i momentarily grounded the single black wire ...from the bike to the control unit... with a screwdriver to the frame, and boom! lit right up!( after a spark or 2 from grounding it out) the wire is beside the 4 wire harness that plugs into control unit, the black wire also hooks up to the control unit but is not in the harness, its separate. unfortunately parts are pricey for this bike as far as electronics. had plans of doing a decent resto on it and moving it along in hopes of getting another Honda express nx 50, but i kinda like the thing! will prob end up with another scooter haha... the bike is looking great now, just not running to swell... any input would be appreciated