If you go for the 118 you will be put in the modified class. If it's a fully worked engine, it'll be in the unlimited class. Unlimited has a 160cc Honda engine throwing down 20+ hp. Get in touch with Neil if you plan on racing the 118cc lifan. If it shifts from an engine transmission, you need to pick one gear and use it for the entire race. I can shift (for now) because my hub shifts, it's happening on the bicycle side.
All I'm saying, is if you plan on racing, make sure it's legal for the class you plan on running it in. Try to bring all the safety gear required, you might be able to rent, or borrow gear.
Neil can confirm, don't take this at gospel, but I believe anyone can show up and pay just for practice day and also get to play during morning practice before the races and during lunch break. I might be wrong, confirm with Neil before attempting.
I have 1 coming for next bike. I was looking at using a cvt, but then I'd have to go with a jack shaft too or a HUGE rear sprocket to get an acceptable gear ratio. a chain drive for 79cc predator will fit. everyone is making Honda clones, but the bore and stroke are slightly bigger than the 79, 99cc cousins. other than shrouds and tank, it looks like so many others
LifanPowerUSA has some tech pdf's if you poke around their site a bit, incl a lot of dimensions and stuff ads don't mention. mine is LF160F-AQ
I'm gonna love the low end pull the 118cc will give. 2x more than HS 49cc haha.
Home Depot is where I got mine for, $139 +tax. I'll update as I piece it into my frame
Hey there morbid- welcome. Unfortunately your question is to vague to answer. Many engine frame combos will work. You can start with a frame you like and look around/ ask to see what would work. Or decide on the engine type you like and find a suitable frame. Perhaps why you want to build (if that is in fact why you ask) is the first question.
Whatever you do- best of luck.