This is an 83 650 Maxim.
Had the gas tank off to have it painted so the gas was drained out.
Just before that the oil was way overfilled so drained it, and changed it and the filter. Due to the overfill the carbs had been sucking in oil that had blown up into the air filter box via the tube from the crankcase.
Got it all back together this evening, and could not start it for a long time, though it had run very well before. Figured perhaps no fuel, and put a bit in each cylinder. Saw lots of spark, but no action, didn't seem to fire even once. Thought maybe I flooded it, not sure. Finally drained the battery trying to start it, and then gave it a boost whereupon it started immediately, but would only keep running if it had some choke.
Went for a drive thinking it might clear up, and then it would indeed idle without choke. Now however, it has trouble accelerating until about 3000 rpm, and then something kicks in and everything seems right with the world. It almost seems as though it's running on less than all four cylinders, yet I am inclined to think it's fuel/carbs due to the oil being sucked in and the gas having been drained.
What should I look for? Recall the bike ran great before the oil overfill and the gas tank being painted.
TIA,
Jim

It seems extremely unlikely that you overfilled the oil to the point where it would find it's way into the carbs.

I'd take off the carbs and clean them up - particularly the idle jets, they sound clogged - clogged idle jets would explain needing to bump start the bike, poor idle, not idling on all cylinders, and the surge of power around 3k when you no longer use the idle circuit.

I know it seems unlikely but yes, it as overfilled that much. I thought it was empty but it was full and added 2 1/2 litres. Pretty embarrassing; usually I am much less clueless. The air cleaner housing ended up about 1/3 full of oil, since the drain tube was clogged. It was a real mess but anyway that's been dealt with now.
Thanks for the idle jet tip; makes sense so I will take a look at that.
This discussion board is great.
Jim

I looked in the Haynes manual; is the idle jet the "pilot jet"?
If so that appears to be an air jet in which case I couold see how it would be clogged now.
Thanks,
Jim

Jim, there is a pilot jet and an air pilot jet. The pilot jet (idle jet) is accessed by removing the float bowl from the bottom of the carb, which entails taking the carbs off the bike. The air pilot jet is found under the chrome caps and diaphragm on the top part of the carb and these can be accessed without carb removal. Both can get clogged.

If you've had oil in your carbs, you are going to want to completely disassemble and clean them. Oil is dirt magnet and even if all your jets (fuel & air) aren't clogged now, they probably will be real soon. Once you get it all back together, I'd run a can or two of Seafoam through the system just to make sure everything is cleaned out. If you have the YCIS system, you will want to run a rag and some solvent down that tube as well to get all the oil out of there.

The reason you are getting the "bump" at about 3,000 RPM is that the engine runs off the idle jet when idling, but the main jet kicks in when you come off idle and that is why the engine seems okay above 3,000. Which leads us to think it is your idle jet that is clogged, but if you're that far into the carb you may as well check everything else out to. It's an easy afternoon project though.