91 1100 bogging over 6000 when warm

[jhawkins]

This seems to be a very peculiar problem. 1991 1100, d&D exhaust, K&N filter in stock airbox. Mains 115, needles 1 notch up, 3 turns out on the pilot.

Bike starts, runs fine. Pulls hard all through the rev range for about 2 -3 KM. As it gets warmed up it stops pulling hard at anything over 6000 rpm.

Example:
Tonight I went through the petcock and carbs and took it for a test drive. Bike was running very hard at all rpms on a 3 km round trip. I started a second round trip and as I was pulling through about 2000 below redline in 2nd gear, it immediately lost power, almost like a switch was thrown. After that it would run hard up until about 6000 and then bog down, not able to accelerate through it.

I have been thinking fuel problems, but everything seems to be perfect in the carbs, new Orings in the boots, no vacuum leaks. Petcock seems to flow really well, floats set fine, nothing in the carburetion seems off.

Two different sets of coils have had the same result, Valves have been verified. The only thing that I can think of that is left is the CDI/Igniter.
Any thoughts on if it might cause the problem?

Any and all help is appreciated

[steves]

What do the plugs look like?

[jhawkins]

What do the plugs look like?

Hmmm, good question, I have not pulled them since my last major attempt to resolve this last fall. I will pull them tonight and have a look. I suppose it could be fouling, never crossed my mind before.

They were brand new last fall and there was no change from the previous set that were in it.

I know the jetting is not perfect, but it is pretty darned close judging by the power it is making, it is a monster for the first few KM.