I mounted a Saito 100 in a UCD and I put it in inverted. The carb ended up nearly 1 inch below the fuel tank which was not good news. That would lead to fuel loading and flooding and probably hydrolock. I ended up buying a Cline regulator which fixed all of those potential problems. My engine runs great with the cline. The cline is a demand regulator that only supllies fuel to the carb when it requests it. It slightly pressurizes your fuel tank and creates consistant fuel delivery throughout the entire run of gas which is great. You can find out more about the cline regulator at
Jim Clines Website . It does cost $60.00 but it is worth it. There are also some threads here on RCU concerning Cline regulators and perry Pumps.
Cline Questions
Cline Regulator - Inverted Saito 100
Cline VS Perry Pump
The nice thing about the cline is that once you put it in there is really no adjusting to do other than the standard idle setting adjustments..