29-08-17, 10:14 AM
Someone needs to find a good misfire diagnostics thread and make it a sticky!!
Swap the caps and plugs over between cylinder 2&3. They both spark at the same time (although only one fires, as it's on its compression stroke while the other is on exhaust stroke), so if the issue changes cylinder with the swap you know its the plug/cap/coil, or if the problem stays with cylinder 3 you know it's a carb issue (air/fuel).
Issues with cylinder 3 - I tend to lean towards a plug/cap issue as if the bike is left outside on the side stand, water sits around the top of that plug and corrodes it.
Also don't always assume that problems that change with rev range are always the result of a carb issue. The carbs do change the air/fuel mixture through the rev range, but this also changes the resistance of the mixture in the cylinder and will create a misfire at certain revs if you have a weak spark / electrical fault.
It may very well be the carbs. But it's not the first job I would be rushing to do with a misfire.
Swap the caps and plugs over between cylinder 2&3. They both spark at the same time (although only one fires, as it's on its compression stroke while the other is on exhaust stroke), so if the issue changes cylinder with the swap you know its the plug/cap/coil, or if the problem stays with cylinder 3 you know it's a carb issue (air/fuel).
Issues with cylinder 3 - I tend to lean towards a plug/cap issue as if the bike is left outside on the side stand, water sits around the top of that plug and corrodes it.
Also don't always assume that problems that change with rev range are always the result of a carb issue. The carbs do change the air/fuel mixture through the rev range, but this also changes the resistance of the mixture in the cylinder and will create a misfire at certain revs if you have a weak spark / electrical fault.
It may very well be the carbs. But it's not the first job I would be rushing to do with a misfire.
-suck-squeeze-bang-blow-