I have just stripped down the M-58 carb on my U-model and for good reason after what I discovered in the bowl (the crud explained the crappy running). Now I have it starting easily and idleing reasonably well, but when I am running it runs with enough surge to make it do that horrible thing where the engine seems to be fighting with the drive system at low speeds (little surges if you know what I mean), as well as a type of RPM over-run when clutching to change gears, or at idle. It seems to take a while for the revs to settle down to an idle. Could this be an air leak in a gasket or flange, or another problem. I had the idle needle at about 5 turns and the high needle at about 2 turns which is about what the manuals recommend (plus the usual minor tweaking for a decent idle).
Does anyone have any ideas why I cannot get the thing to run a little smoother?