Quote from papsck on 01.09.10 at 00:10:24:


Stock size is a 40mm Hitachi CV carby. Rule of thumb says, that a CV carb will only allow about 2/3 of the available diameter to be used, both the 36mm (I suppose they were Mikuni VM36) and the 40mm Dellortos should be fine. In terms of jetting... hmm... I would stick with the Mikuni VM because the slides are hardcoated, whereas the Dellorto carbs are brass only (with a thin plating of chrome) and therefore wear out a lot faster, especially in terms of the needle jet - trust me, I know... I have been riding old KTMs for quite a while).

Mikuni VM36 jetting (no responsibility taken, but this is roughly how my XT500 is jetted, which could be called "half a TR1 engine")

Pilot: 25
MainJet: 120 or 125 (go for the richer jet to start with)
JetNeedle: Middle position (3rd notch in my case)

This should (with some fiddling) at least give you some sort of idle and then try to adjust the mixture-screw (which is on the front towards the engine) about 3 full turns (+/- 1 turn). This should give you something that should be rideable. Once you're this far you should check the plugs and see what color they are and whether you have any flat spots or the like.

Hope this helpful in any way to you

Cheers,
Greg