The bike has been running great for quite a while, but now has a new issue. At least, I don't remember it doing this before.
82 1100GK. Stock air box. 4 into 1 exhaust. 1 size up on pilots and mains.
Only when running at WOT through 1st, 2nd, and 3rd, it will start to stutter as it climbs in the rpms. Starting around 6k and intermittently going all the way to 8k. If Im cruising along in 4th or 5th and I twist the throttle, it wont do it. It only seems to occur when the engine is under heavy load and high rpms.
To me, it feels like it's running out of fuel for a quick second, then it's ok, then it's not, then it is, etc... But I guess it could also be electrical.
The bike runs fine otherwise. If you don't get after it, it's happy to just cruise around. However, it does occur when downshifting and attempting to pass. So that's not good.
So far I've checked the following things:
Carb sync. Perfect.
Air leaks. None that I can find. The carb boots are new along with the seals and the air box has been sealed up.
Checked float heights, again. Within spec and fuel height for each was measured with a tube at the carb / bowl body.
Replaced bowl plugs because they were rock hard. No change.
Checked for pinholes in the slide diaphragms. None found. And all 4 appear to slide down at the same rate.
Valves checked recently, all were within spec.
Carb has been completely torn down and ultrasonic cleaned within the last year while troubleshooting a different issue. O-rings replaced.
Coil relay mod performed. Good voltage going to the coils.
Rectifier was previously replaced by the PO. I have a voltage meeter on the bike and the voltage appears to be stable.
The issue persists when switching the petcock to prime (gravity feed vs vacuum). Also, the petcock was replaced back when I first got the bike.
Some things to note. My plug wires do have some cracks near the boots, but not from age. Because the PO routed them wrong they were really hard to get off for a while so they ended up developing some cracks near the boots. The wires are not replaceable (original coils) so the coils will need to be replaced with them if I go that route.
Also, when I rebuilt the carbs I didn't replace the float needles, but I did inspect them and they appeared to be fine.
Anyone have an idea of where to focus my efforts next?
82 1100GK. Stock air box. 4 into 1 exhaust. 1 size up on pilots and mains.
Only when running at WOT through 1st, 2nd, and 3rd, it will start to stutter as it climbs in the rpms. Starting around 6k and intermittently going all the way to 8k. If Im cruising along in 4th or 5th and I twist the throttle, it wont do it. It only seems to occur when the engine is under heavy load and high rpms.
To me, it feels like it's running out of fuel for a quick second, then it's ok, then it's not, then it is, etc... But I guess it could also be electrical.
The bike runs fine otherwise. If you don't get after it, it's happy to just cruise around. However, it does occur when downshifting and attempting to pass. So that's not good.
So far I've checked the following things:
Carb sync. Perfect.
Air leaks. None that I can find. The carb boots are new along with the seals and the air box has been sealed up.
Checked float heights, again. Within spec and fuel height for each was measured with a tube at the carb / bowl body.
Replaced bowl plugs because they were rock hard. No change.
Checked for pinholes in the slide diaphragms. None found. And all 4 appear to slide down at the same rate.
Valves checked recently, all were within spec.
Carb has been completely torn down and ultrasonic cleaned within the last year while troubleshooting a different issue. O-rings replaced.
Coil relay mod performed. Good voltage going to the coils.
Rectifier was previously replaced by the PO. I have a voltage meeter on the bike and the voltage appears to be stable.
The issue persists when switching the petcock to prime (gravity feed vs vacuum). Also, the petcock was replaced back when I first got the bike.
Some things to note. My plug wires do have some cracks near the boots, but not from age. Because the PO routed them wrong they were really hard to get off for a while so they ended up developing some cracks near the boots. The wires are not replaceable (original coils) so the coils will need to be replaced with them if I go that route.
Also, when I rebuilt the carbs I didn't replace the float needles, but I did inspect them and they appeared to be fine.
Anyone have an idea of where to focus my efforts next?