I have a 2001 883 Hugger that was upgraded to a 1200. The bike has 17000 miles on it, the new engine about 1100. Last year, I rode for about 50 miles, was off the bike for about 20 minutes, returned and the bike wouldn't start. I threw it in the back of my truck, got it home and started it. Since it was the end of the season I didn't mess with it. This year I drained the fuel, cleaned the strainer, opened up the carb and gave it a good cleaning. Checked the plugs and they were pretty black with soot so I cleaned them and put them back in. Rode the bike for about 30 miles and felt it stall, downshifted and gave her gas and she relighted and I was able to get to work; another 20 miles. That same day, left work, got 7 miles with some stalling and relighting before she finally shut down. She sat overnight in a driveway, trucked it back to work and it started right up but after idling for about 10 minutes it shut down and we discovered there was no spark. Cleaned the coil connections and replaced the ignition module, started it but was having intermittent misses. Rode it 8 miles with some stalling and relighting before it died again, this time with a loud ping sound. Towed to a dealership, got it off the truck and it started. Any ideas?

 

Sounds like it's running way too rich to me (based on available info) and fouling the plugs causing them to greatly diminsh spark for combustion.

 

Maybe, just maybe, bumping up to 1200cc's required new jets in the carb - and perhaps they were incorrect, thereby causing an over rich mixture. Or the carb was incorrectly tuned to the new cc's. The mixture screw on the bottom of the carb is plugged so that it can't be tampered with. You can drill that out and put an aftermarket screw in it (that you can reach and turn by hand) for adjustment. I'd pull the carb and look at it first. Perhaps you can talk to the last owner and see what he actually did to it as well.

 

check the enrichener cable, and the enrichener its self for sticking open /leaking .
also look for float sticking (overflowing carb bowl)

883 to 1200 by its self does not require jetting change ..
same afr but just more volume.