help me sort this out

Cool, thanks for all the replies and videos. it sounds like the tomy/plarail out of japan are better quality than the fisher price trains at walmart. I just bought a chuggington brewster for my son on line and excited to see the potential quality. im not going to bother getting the new trains and converting the wheels, just make sure im buying the right thing

I have some older Thomas trains that I picked up at a kids consignment sale, including a (i think) bumble bee james. I'd like to do a 'tune up' and mabe some modifications. im not in any rush at this point, but any advice or suggestions (usually) from past experiences on do's or donts on putting in a faster motor? see attached photo, is this what I would be looking for?

I saw a video on how to tune up an old train, and suggestions (or links already here) would be helpful.
Thanks
Cheers.
Kevin