17-09-16, 10:29 PM
As said, check that the leads to 3&4 are the right way around.
Then Swap the spark plug leads around so swap 1 & 4 with each other, and 2 & 3 with each other. These pairs actually spark at the same time, although being a 4stroke engine only one of the cylinders has petrol in and fires.
See if the problem moves with the leads.
Problems with cylinder 3&4 are quite common as water and crap sits around the plugs and caps when the bike is outside on its sidestand. Especially in the crap weather we've had.
If you think it's the carbs try some redex before taking them off/to bits. It's a ballache of a job that rarely solves the problem.
Then Swap the spark plug leads around so swap 1 & 4 with each other, and 2 & 3 with each other. These pairs actually spark at the same time, although being a 4stroke engine only one of the cylinders has petrol in and fires.
See if the problem moves with the leads.
Problems with cylinder 3&4 are quite common as water and crap sits around the plugs and caps when the bike is outside on its sidestand. Especially in the crap weather we've had.
If you think it's the carbs try some redex before taking them off/to bits. It's a ballache of a job that rarely solves the problem.
-suck-squeeze-bang-blow-