Does anyone out there know what jetting there running in the Dellorto carb.  I've got a 85 main and bike seems to load up and run rich over half throttle.  Have gone thru carb, and have points and timing set correctly.  Bike starts first kick runs great on bottom but loads up when you need to ring it out on a uphill section.  Plug is dark.  Just don't want to burn up the motor.  

Try dropping the needle a notch or two first

hope this helps with carburettor jetting it is SWM specs

I think your bike has the same/similar engine as mine. Which is an Motogori as I am using the clutch cover on my bike which is the same as  the 312TXR. 

 

SWM MODEL SPEC SHEET.xls

Be aware that the TXR have a later Dell'Orto PHBH 26, of type SD which is a Mikuni clone and fitted with an air screw.

The factory adjustment for the 240 and 276cc model are:
main jet:      88,
idle jet:        58,
nozzle jet:   BN 266,
clip:             2nd from above,
slide:           45°,
air screw:    1/4 out,
float:            8.3 gramm,
needle:        I have to look up, if of interest
gas valve:   200