Topic: Tuning issue

[eigenvector]

Tuning, not turning, so far my recently rebuilt CB550K is purring like a kitten.  Rides good, has great power, sounds phenomenal.  All in all it is riding just like a bike of that vintage should ride.

Well, except one thing that I don't quite know where to start.
It has excellent power for a bike of it's displacement, until you get to 5000 RPM.  Darn near at 5k, the power drops off noticeably, enough that I have to shift up to drop the RPMs to continue accelerating.

My working theory is that this is my float bowl levels, that it just can't suck in enough gas.  On that score it might be my gas flow - like a plugged filter.     I can certainly try replacing the filter - and should anyway just for peace of mind.  But does anyone else have a better idea about the source of this drop off in power? 

Last thing, I am getting an intermittent pop on decel at the lower end of the RPM range - 2k or so.  My assumption here is that it's a simple air leak, but I'll be danged if I can find one.  The plugs tell me that this bike is running approximately at optimal mixture, maybe a touch lean.  One of my cylinders is a little cold - #4 and the last one in line for fuel.

[Steve_K]

Here is my thoughts, I would check resistance of plug caps and I would also check if the points are sparking, sign of a bad condenser.  I think the plug caps should be about 5k resistance.
Steve

[eigenvector]

Doesn't appear to be either of those.

Plug caps check out a 4.7K, points did not appear to be acting unusual. 

I'm glad I did the checks, as soon as I turned on the fuel petcock #4 carb began spewing fuel all over the place, piece of grit or something.  If it isn't one thing it's another I suppose.