Ive been on the quest for a better trail bike over the last few years. Ive been doing hare scrambles and quite a bit of woods riding on my YZ125, and while it does pretty damn good for a MX setup, I want something with a shorter seat height, wheelbase, and lighter weight. Ive ridden a few air cooled 4stroke machines, but find them heavy, undersuspended, and outdated. A KX100 chassis seems to be exactly what I'm after, and Ive been thinking about an engine swap, but in order to save a whole bunch of fabrication and pain in the ass of another project, I thought why not mod the stock engine? Theres a whole host of mods that have a massive effect on the two stroke, like port-time area and head chambering that I'll have to farm out, I can take care of the rest (carb, exhaust fab, drivetrain, FWW, etc...). Basically what I want to know is if tuning the engine for extreme low-mid will be a waste in general. There's enough gnarly, tight, black timber where I've chosen the XR80 or XR100 over my 125. I can sacrifice a few ponies up top to get something rideable just off idle. Some of the better trail bikes Ive ridden are a 150cc cammed and heavy sprung KLX125, and a stock XR200, but there is quite a bit to improve upon. Ive read a few threads on here about converting the 100 into a trail machine, but have yet to find anything on tailoring the power curve by way of more extreme engine mods. Anyone on here have any experience in this particular department?