A good toy is a indirect read IR thremometer. Point it at the head and the exhaust after a rid and see how close the temps are between CFLs. Mine run within about 20F of each other when fully warm with the left always hotter, both the head and the exhaust. Also, checking the plugs now and again. I prefer a bit too rich mixture in the net, keeping the plugs a bit black, figuring it is a cooler running mixture.
Be careful choosing and using an IR Thermometer. I have one I bought a while back, and I was using it to do this exact thing (for my 1928 R52). While reading the temps on the running motor, the thermometer suddenly stopped working. The company pointed out that the low end model I had bought was not shielded against the EMF generated by the plugs. They did give me a refurb unit, but now I never turn it on while the motor is running.
Good eye...... Yes, both had cracks and hard. I changed those out a couple of days after I took those pictures. And yes, I felt a definite difference in the way it idled and at speeds. These are just those little things I'll be replacing as I go along....... I just got carb rebuild kits delivered yesterday. Just one more thing I want fresh for me. This bike is a fantastic runner.
Yes, after cleaning up what appear to be original clamps, I used some high gloss 500 degree engine rattle can. Only used it because it's a "harder" paint. Nothing to do with heat....... Plus, I like the look.
Oh, definitely runs better or might just be my imagination...........