oh i remember modifying my rm125 when i was 18, thought advancing the timing made if go like hell, till the piston melted, still got the piston to this day, i learnt a lot that day.
on the other hand on my pe175, i made the rear shocks longer, which made it a lot better.
with my friend he built a rmx from ebay parts and for a few months now can not get spark from it,
which i beleave is from not knowing the bike well enough, for eg. is that the right coil or flywheel
and is driving him mad!
does mixing and matching different models make the bike better? eg from drum to disc!
or does it make it a pain to order parts when you aren't sure what front forks are on there.