Weak spark?

[MattEaton_]

How’s everyone doin?
I’m jumpin through hoops trying to find out what’s going on with my front cylinder it was fine for a week now it’s back again, it runs mint I rebuilt the carbs and synced both of them after winter, so what’s goin on is once the bikes hot it looses power and the front cylinder just gives up, wait a few minutes and it idles and rides fine for maybe a quarter mile then it happens again, I’m getting spark, when I unplug the front spark plug wire it still idles with out changes and when I unplug the rear one it stalls, I’m getting fuel as well, if anyone’s ran into this issue it’ll be awesome to know what’s causing this

[Herb]

Are you sure it has spark when you unplug it? I have had coils and spark plugs go bad when hot and under compression. What is wierd is that the plugs can fail but they are shorting out to ground and it will appear they are firing when test equipment is used.

I would try swapping the plugs between cylinders and see if it changes. If it doesn't try swapping coils.

[FallenAngel]

How’s everyone doin?
I’m jumpin through hoops trying to find out what’s going on with my front cylinder it was fine for a week now it’s back again, it runs mint I rebuilt the carbs and synced both of them after winter, so what’s goin on is once the bikes hot it looses power and the front cylinder just gives up, wait a few minutes and it idles and rides fine for maybe a quarter mile then it happens again, I’m getting spark, when I unplug the front spark plug wire it still idles with out changes and when I unplug the rear one it stalls, I’m getting fuel as well, if anyone’s ran into this issue it’ll be awesome to know what’s causing this

I know this is an older post but as there is no post that you got it fixed here goes
does it just die or sputter then die

[Lechy]

Gravity will fill the rear carb but the front carb needs the fuel pump. try draining the front float bowl next time it cuts out.

[Kingkoa1]

I had the same problem after tuning up my bike...I thought it was the carbs, or the spark plugs and coils.... it was my battery! As soon as I put a new battery in it ran like a champ!I cleaned the carbs 4 times and replaced the coils and plugs and it would run for a bit then it would die and I would have to trickle charge to get her going again.i thought the battery was good because I started up the first few time, anyways try changing the battery.

[MattEaton_]

My apologies haha you guys were a big help diagnosing what exactly was going on I wanna say it was an electrical and a sync problem, I changed the battery terminals drained both the carbs (found out my petcock was clogged) re synced the carbs, make sure both the carbs open and close at the same diameter and time, my front one was pulling more way more air then the rear plus got new coils and plugs