Hi pretty new to here,

i recently bought my kids a quadzilla r100 2021 witch they absolutely love and spend hours on end riding it
but with in a matter of 2days already they are looking for more power I didn’t expect them to pick it up so quickly only being 9 and 10 years of age, I’m interested to know if there is any relatively cheap mods to get a little more out of it? But still remain reliable we are looking for more lowdown power. Thanks in advance!