Thanks. I think you're right about the 1G8. Too big for what I need.
The DT100 is the same bolt spacing as some of the YZ85s. The plan is to run a YZ85 V-Force reed block on it with a Mikuni TMX35 running methanol. If I can't get a carby boot to do this, I can always back it off to a VM28 (which I already have). That will fit in the carby boot I have. Will lose a little top end but if it don't fit, it don't fit.