I purchased an old vfr nc21 10 weeks ago which had stood outdoors for 8 long years. It took me 2 weeks to get parts together and finally get it going. Ran lovely.
Day after running rough then wouldn't start. Carbs were taken off and cleaned out. Pilot and main jets blocked.
Put back together and started nice. Now some 9 weeks later I have a miss fire problem on the front left cylinder. It kicks in and the down pipe heats up like the other with 3/4 choke??? (i'ts not the tank. Its been cleaned and por15 sealed and all fuel hoses are new)
All new plugs, new needle valve on that carb (carb seat filters have come away on this carb but float bowl still fills up). I checked and the plug sparked.
Right the day after it run lovley on 4 and I went for a short 5 mile ride no issues at all and huge grin on the face from that v4 sound.
Today, some two days later I just started her and she is only running on 3 again and I just can't work out why. I swapped the front coils over to see if the missfire changed sides and it did not. I swapped the two front ht leads over and it run great on 4 for ages but now is back onto 3 again. I put it back in my garage, closed the door and walked away.
Has anyone got any ideas of what could be causing this? I don't mind taking the carbs off for the 4th time in as many days as I have a spare set of inlet rubbers and clamps just in case one splits. I'm getting very good at putting these back on now.
I have (wait for it) spent over £900 on it so far and have to carry on or i'll lose the lot. I plan to keep this classic sports bike for good as I'm not doing it to make money, more of a rescue job.
I just can't work out if its fuel related of electrical. Heeeeeelp.