I've got a 79 Puch Maxi. Ran it all last year without any major trouble. When I started it up this year, it was having some trouble.
Couldn't get it over 25 and would stall out occasionaly for the first 5-10 minutes. It wasn't running great, but it was running reliably.
We (Brett Dan Russ and I of 50:1) took the carb off one night to try a bigger jet, make sure everything was clean, etc. to see if that would improve the performance. Tried a bunch of different jets, swapped out spark plugs, no luck. Put it back together the way it was, but then it wouldn't run at all. Sometimes it doesn't catch. Sometimes it does, and dies out immediately. Sometimes it will idle and you can give it gas no problem. When it does get running, and you give it gas, it will go strong for a bit, drops out occasionally but will come back. Eventually (usually pretty quickly) it dies off.
To date we have redone the wiring hub, clipping the ends and stripping fresh wire, put in a new condenser, put in new spark, put in new points, checked the compression, and cleaned the carb a billion times. Still behaving the exact same way, the only difference being that when it does run now, it runs much better than before we did all this.
The points and the timing seem fine. Fuel flow is fine. My gas tank is nasty, and I don't have a filter in my fuel line, but I don't think this is the problem. I will add a filter and clean the tank out tho.
We're pretty sure it's an electrical problem. We have checked the spark and seen it firing strongly and regularly. Then we put the spark into the cylinder and try the bike a few times. Take the spark out again and it doesn't spark or sparks intermittently. We've checked the wiring on the boot and it seems fine. One of the weird things is, when the bike idles pretty well for a while, it dies out when I get on it. Spooky.
Any Puch electrical gurus out there with advice?