Cylinder 1 misfire/not running
My 1982 Honda CM200T Twinstar has been having some issues with cylinder 1 since I’ve owned it since May.
Cylinder 1 never seemed to run perfectly, like an intermittent misfire, on the throttle it’d run just fine and smoothly.
I didn’t ride it much due to weather, maybe just a couple times a week. I went to start it up today and cylinder 1 was just not running. I thought it would run fine again after it warmed up as it’s only 14°C out.
Anyway after shutting the choke off, cylinder 1 would still not run and would on a rare occasion fire. Trying to rev it would start to kill it like it was cold. After fully warming it up I took it for a ride, and only one cylinder. Both would occasionally fire together and I’ve have power, but it was mostly just operating on cylinder 2.
Onto the testing, cylinder 1 plug was black and wet with fuel, cylinder 2 plug was black but dry. Both tailpipes are sooty but cylinder 1 more-so. There is also what I believe to be fuel vapour coming from the Cyl 1 exhaust.
Swapping the plugs around and it ran just like before, both plugs have a perfect spark.
I tried starting it with the fuel on, shutting the fuel off, the bike would slowly run smoother and rev up until dying.
The previous owner who restored it put a cheap aftermarket carb in and that’s my suspect. There was some fuel sitting on the top of the carb as well. Definitely running rich but I’m not great with carburetors and older motors.
Anything helps as of right now, not really wanting to play $200/hr for a shop to diagnose and fix.