Sorry clutch cable problem (for the ump-teenth time)

[Drum Pro]

I can't seem to get into first and I can only get from 2nd to 3rd and not 4th. I think it's a cable issue. What size cable do I need to buy if this is indeed the problem?

[az_slynch]

There are a pair of cable adjusters on the forward face of the shift box, just below the fan shroud and aft of the kickstart. There's one for the upshift cable and one for the downshift. You can adjust them with a pair of 7 or 8mm combination wrenches. Loosen the jam nut on the adjuster before trying to turn it. Turn each adjuster out 2-3 turns and set the jam nut. Don't tighten the jam nut too hard or you could snap the adjuster, just get it snug. Try the shifter again. If it's still a bit too sloppy, try another 2-3 turns on the adjusters.

The cables will stretch over time and will be aggravated by trying to force gearchanges when stopped. They need to be re-tensioned every so often. The alternative is to pop for some OE Vespa shift cables. I have 20K on my 33 year-old cable set with only and occasional adjustment.