02-06-15, 01:34 AM
It's a mechanical system things wear out and break. Don't feel down about it it's still a good bike it just needs a small fix. Does it happen more when the bike is wet? You're dropping a cylinder and you've tried new plugs and it's still not running right but with the plugs out you're getting good spark so that rules out a few things for now. You can assume the plugs and coils are probably good. Next I'd do the old trim the leads and see if that helps. The leads degrade over time and the insulation cracks breaks down and they start to arc to the head and you loose spark. It seems to happen worst at the ends of the lead where they screw into the cap so try trimming a bit of lead off the end. Did that help? Next I'd try swapping the caps around, taking note which cylinder was the dodgy one. Did the problem follow the cap? If not I'd try wrapping the leads in insulation tape as a temporary way of ruling them out. Did that help? I think you can assume the coils are good but still it'd be no harm swapping them and going for a ride. Did the problem move to a different cylinder? Do that stuff first because it's the easiest. If none of that helps you'd probably want to check the carb on the dodgy cylinder. It could be over fuelling on that cylinder. So check the float and needle and make sure it's seating right and at the correct height. Give the carb a good clean and that'll probably sort it. Have you done any work on the carbs before? What mileage is on the bike. I'd say they just need a good clean.