I tried an 800 and it didn't do any different in the MPG department, I think there is a point where atomization only gets so good and the primaries on the 850 are reasonably small. Mabey if I was only concerned with MPG at 50 MPH the smaller one would have showed very small gains but most of my testing was just real world driving in town and on the highway at 70-75 mph. I may be doing another one soon and it will turn less RPM so the smaller carb might show some small improvement.

Has anyone on here used a A/F meter when tuning a t-quad, i think this winter i may install my modified stock intake and play around with my 71 t-quads but right off the bat i want to install a A/F meter seems like it would make life easier with the jets, rods, float, sec air door gap, sec air door spring adjustment etc..etc..etc..