The bike is somewhat a bitsa, as the motor that came on it was trashed. So the 1971 T500 has a 1973 motor on it now. So there really isn't a "stock" configuration that's 100% correct. At the moment, it is configured like this on both cylinders:
- '73 cylinders (smaller/more restrictive porting)
Early (short) intakes
Early Air Box and Boot, with NOS filter installed
145 Main Jet
P-5 Needle Jet
5FP8 Jet Needle, in 3rd slot
2.5 Throttle Slide (cutout towards rear)
30 Pilot Jet
New genuine Float Needle/Seat, 27.0 mm Float height
The engine started off way too rich. I did have a late model Air Box (it *is* more restrictive, as I found), but with the new early model Air Box, I now have the idle circuit set pretty well. Screws are out ~2.5 turns, but have 27.5 Pilot Jets on the way to try.
The bike starts on 1 or 2 kicks, and now idles well, with minimal smoke. Where it lacks at the moment is at small throttle openings. Twist the throttle 3/4 to WOT, and she pulls and sounds great. But at a civilized throttle (pulling from a stop, or just holding a cruising speed at 2500/3000 RPM) it sounds/feels very heavy.
Checking the spark plugs after riding a bit, it is obvious that it is still running rich. My gut feeling is the next step should be dropping the Valve Needle down a notch to see if that helps. I also have a pair of both P-4 Needle Jets and 5FP17 Jet Needles, but I figure baby steps, right?
All input is welcomed.