I am new to the sport; purchased an '85 KDX 200 2 months ago and love the bike. However, being the rookie I have a couple of basic questions. (1) height of bike. I am 5'9" tall; both toes touch the ground. I have already lowered the bike the half inch or so that the adjustments allow. Almost all the other riders I watch look like they can flat foot their bike with no problem. What is recommended? I cannot find much info on this topic. (2) the bike came with a NGK8ES spark plug and ran fine from day 1. The manual says to use a 9ES and changed it yesterday. Is it my imagination or could it have a little less low end with the 9 plug? another words could the bike have been tuned to the 8? Thanks in advance...