Have a strange fault on a 300 at the moment. It blew the whole system a couple of months ago. Battery dead, no spark with a new battery. tested the wires to the CDI, all OK so swapped CDI, it ran but, having been fooled before, I checked the charge rate, well over 18v, so overcharging had blown the battery and CDI. Put a new regulator on as well, and sent it back. Few weeks later and back again with a misfire when hot, tried cleaning the carb and another coil, no better. Fitted a new trigger coil and hoped for the best. Back again it came still misfiring when hot. Fitted another new CDI and took it for a long run, seemed better but, thinking the regulator may be overcharging intermittently, on my way back to the workshop I switched the lights on to cut the charge rate. Came in, switched the lights off and the bike died instantly. Started it up again, and back to misfiring, lights on, no misfire, but it wasn't overcharging, 14.4v max is about right. 300s are peculiar in having 4 different CDIs, depending on year, so our suppliers may have sent 2 wrong CDIs for a 95 machine, or the non genuine CDIs may be faulty (RM Stator). We are going to try a different supplier for a CDI and regulator.

 

Has Atv been wrecked or hit in the front end? That lenar diode [ Silicon Rectifier] or damage to the harness at connection box

 

Honda ATV 1995 OEM Parts Diagram for WIRE HARNESS | partzilla.com Photo#12

 

I have had the best luck with Ricks Electrical red CDI box on these model

 

Did wonder about the diode, never been able to work out exactly what they do. As I wrote above, the faulty voltage reg blew the original CDI and battery so could have damaged the diode too. Been trying to avoid removing the front plastic, 30 year old rusty fasters are never good to get off on a 300 front.

 

You get to connector box after removing fuel tank use 10mm socket to remove connecting box bolt in the door and diode is right there in harness or remove left inner fender just an ideal yes sounds like you got things going in the right way

 

The 300 was put to one side for a while, we gave the owners a courtesy bike so they were not pushing for it and boss's son's 420 Auto cooked its alternator again, right in the middle of lambing time, so that took priority. Anyway, new CDI and voltage reg came so I took the front off, one sheared rack bolt despite warming it but otherwise not too bad, put a spare diode in and the new CDI. Won't start, no spark. Took a look at the box and "Fits 300, 1988 - 2002" got to be lies as there were 4 different CDIs between 88 and 2000 when production ceased. So I put the other CDI back on, Tried the new voltage reg and same as the previous one, up to 14.4V max. So I have given up, and told the owner to "run it with the lights on and see how you go".

Why can't aftermarket makers get things right. A few years back aftermarket CDIs and voltage regs generally worked OK, may not last as long, but now you are lucky if aftermarket even fits. Have an ATC250 in for an ignition switch, no longer available from Honda. One of our parts supplier does them, so got one. Bullet connectors wrong size but a lot more problematic is the key switch far to small for the hole in the dash. Spent a couple of hours messing about, making a plate small enough to fit the dash and bolt on, with a 1" hole for the smaller key switch.

 

Yes in today world bad quality parts are 90 percent of the issues now days it very sad this cheap market stinks