I gave the bike a nice long ride to commemorate it's engine rebuild service point.
Time to change the oil and see if there's anything in there that shouldn't, adjust the cam chain, adjust the valves if needed, check compression, and secure anything that might have shaken loose.
I have noticed a few quirks that probably need to be addressed but not sure of their significance.
1) cylinders 2 and 3 are running hotter than 1 and 4. I don't know if that's because they are behind the tire and therefore subject to less cooling or if it's due to tuning. The pipes are deep blue on top after a long hard ride where they join the engine. 1 and 4 are nothing special - normal 'hot' chrome color.
2) It has a very unstable idle. Sometimes I'll pull up to a light and it will purr along, others I'll pull up and the engine will die outright. I haven't been able to predict which it will do. When it does want to idle it does so smoothly without coughing or racing. I have my idle set to about 1700 rpm - high but I have it there to see if it will correct for the unstable idling. So far it doesn't.
Otherwise, the bike has plenty of power for such a small engine and it is smooth when applied. Doesn't burn any oil. The plugs indicate a "normal" operating engine. Seems to be getting decent gas mileage. And despite my expectations it has a reasonably comfortable riding position, although I think the shifter should be moved a bit closer to the riding peg - but it's not the only bike with this issue.
