william Hutt wrote on 12/31/69 at 16:00:05:I have the same problem with my bike. Mine is intermmittent. I can ride all morning long no problems, then when I get back on it in the afternoon, i'll be riding along about 45MPH start to feel some bucking(surges) as though its not getting gas pull in the clutch and it dies. I then have a hard time starting it.
I have tried high octain gas, no help.
Remove white spacer and adjusted carb, no help.
Found a bad spark plug, replaced it, Problem still there.
Replaced ignition module(ignitor), Problem still there.
Reversed the white spacer and carb adjustments due to black smoke produced after the spark plug was replaced, smoke went away but problem still there.
I am starting to think that maybe the fuel filter in the tank may be getting restricted or trash in the carb bowl.
Anyone have any other ideas?
Easy thing to check is the connections to the coil, these connectors can get a bit lose and cause odd running however as described and since you have had the diaphragm/slide out of the carb this sounds like a hanging slide to me. It dies and is hard to start when you pull in the clutch because it floods the engine because the slide did not close the needle jet as much as it should because the slide is hanging toward the bottom of it's travel because the spring the was not centered on the cover, or the slide was a little dirty, say from oil on your hands, when it was reinstalled or the rubber was not seated correctly in the grove.
I would pull the slide back out of the carb and with a clean paper towel rub it down real clean and wipe out the tube the slide fits in - if that paper towel is dirty when your done it'd bet that was the root issue - this does get worse was the bike gets hotter - I guess the slide expands more than the aluminum tube it fits in and the tolerance closes.
Chased this down twice now you'd think I'd learn!