Jetforce C-Tech starts hard when cold or only with starting fluid?

Hello everyone,

I recently bought a Jetforce C-Tech. I replaced all the parts, including the variator, new spark plugs, cleaned the carburetor, and had new air filters, etc. The jet runs very solidly and, when warm, has very good acceleration/speed. If it's been standing for several hours, meaning the engine is cold, I can hardly get it started without starting fluid. Does anyone have any idea what the problem could be?