Matt-Max
Active Member
Evening Massed Brains!
I've done a bit on the Vmax over the last few weeks and sorted a split diagprhagm, seized thermostat and done a full water flush. Got it back up and running and it would get a little lumpy, as luck would have it I was in the dark garage and could make out a spark leaping from the HT cap to the engine casing, so... One set of new caps and a wire trim later I'm feeling confident. Nope. Still the intermittent extra pop in the exhaust as something in one cylinder decides it fancies igniting.
So, replaced the plugs too. Still no improvement.
Took of the filter cover to observe and number 2 wasn't quite right (diaphragm slightly pinched) resolved that. Still nothing.
Disconnected one cap at a time to clarify the cylinder. Defo number 2 giving intermittent pops and backfires, most notably when changing down. So now I'm thinking right, check the spark using a spare plug - all good all round, nothing looking even vaguely dodgy.
Back to the carbs, if I place my palm or a jam jar lid over the inlet for 1 and 4 the bike will conk out. If I put it over 3 it will blow back fuel (wet palm) but manages to keep limping on. If I try to seal off 2 there is nothing.
Could it be a split somewhere causing air to be sucked in past after the carb? Would that be enough to create the pops in the pipe?
Thoughts massively welcomed!
I've done a bit on the Vmax over the last few weeks and sorted a split diagprhagm, seized thermostat and done a full water flush. Got it back up and running and it would get a little lumpy, as luck would have it I was in the dark garage and could make out a spark leaping from the HT cap to the engine casing, so... One set of new caps and a wire trim later I'm feeling confident. Nope. Still the intermittent extra pop in the exhaust as something in one cylinder decides it fancies igniting.
So, replaced the plugs too. Still no improvement.
Took of the filter cover to observe and number 2 wasn't quite right (diaphragm slightly pinched) resolved that. Still nothing.
Disconnected one cap at a time to clarify the cylinder. Defo number 2 giving intermittent pops and backfires, most notably when changing down. So now I'm thinking right, check the spark using a spare plug - all good all round, nothing looking even vaguely dodgy.
Back to the carbs, if I place my palm or a jam jar lid over the inlet for 1 and 4 the bike will conk out. If I put it over 3 it will blow back fuel (wet palm) but manages to keep limping on. If I try to seal off 2 there is nothing.
Could it be a split somewhere causing air to be sucked in past after the carb? Would that be enough to create the pops in the pipe?
Thoughts massively welcomed!
