Mike,
Awesome project!!!
Guys...adding a little bit of Nitro to gasoline will do absolutely nothing for the performance of your engine...
Now let's get realistic for a minute...Instead of thinking about the fuel for the engine...think about creating an engine for the fuel.
If you want to use hobby fuel effectively, you will need to buy a hobby engine and reverse engineer it to what ever "cc" displacement you deem appropriate...let's use 66-69 cc's as an example, (the larger displacement China engine).
There is not even the slightest chance that the best quality bicycle would handle the horsepower of a scaled up hobby motor.
Buy a 125cc motocrosser frame to install your giant hobby engine...and then hold on and pray!!! When this thing lights up it will make the wickedest roller coaster look like a baby ride!
In order to tune the beast, get it broken-in, and ride a few miles you will need to buy a 55 gallon drum of hobby fuel...yes you're going to need it!!! You can plan on about 3/4-1 gallon per mile if you can hold onto it for that long.
Any thoughts of using ANY component, (or design feature), of the Chinese engine will lead to frustration.
There is only one, 4-cylinder, Top Fuel rail in the world...and I build the engines for it. 90% Nitro...10% Alcohol...here's a video.
YouTube - "Billet Racing Engines" 4- Cylinder Top Fuel Dragster
It is extremely tricky to tune a rolling assembly to run on Nitro...When I say assembly...I mean the whole car!
The carnage, (broken parts), from 50% to 90% Nitro is ten-fold.
Try if you will...and certainly have fun...but I can guarantee you that if you attempt to build an engine that runs on hobby fuel...and it isn't a scaled-up version of a hobby engine...you will be disappointed.
Jim