What weight oil are you using and what are the current ambient temperatures where you ride?
I have a Staton FD w/a Robin 35 and it initially had the same problem, in probably the first 5 hours of use. There is a thread here you can search for that mentions several members had the same problem.
I simply changed the oil, not according to the manual schedule but when it smelled of gas or looked dirty. I probably changed it at the first 5 hours then again at the next 5 hours, then after ten hours. The problem went away, the engine has good power and speed so I assume it was just the initial breakin.
Change the oil, not a good thing to run it with oil thinned with gas.
I live in Southern California and the oil is made for small 4 cycle engines. I have only used the bike about a dozen times and there is no fuel shut off, only a priming bulb to get the engine started. If it's just a break in thing I am OK with that. I just don't want to ruin the engine and have Honda say that I did something wrong and the warranty does not cover it.