Beautiful scooter,
I just had a similar issue with my tomos, felt like a cdi problem, spark was fine.
Weathers been alot nicer lately, I upjetted one size as it didnt have much low end/ middle power but it was fine once you got going.
One or two jet sizes up might do it for you.
Im gonna guess this is maybe your issue since I also have a 15 SHA on my tomos