I changed the float level a little higher than stock (less fuel in bowel) because of my bikes "blubbering" over real rough terrain and it helped my gas milage from the stock setting.Im sure on the stock setting I was loosing fuel from the vent lines over the rougher trails,that was causeing the rough running of the bike.I made my own "power now" out of sheet aluminum (you could use stainless steel)its been a while ago that I made it so I dont remember what guage aluminum I used.It needs to be thick enough not to flex to much or not at all,cut it to fit inside the air box side of the carb horizontally,in the middle of the throat ,as close to the slide without it touching as possible(I used a cardboard templete)and Im guessing I left 10/15mm sticking out into the airbox.I made the first 1/3 of it wide enough to fit into some grooves I cut in the throat of the carb body and epoxyed it in place.I made this by looking at the picture from there web site for the 2-stroke power now,just forget about the cone part of it and look at the flat part.Make sure it DOESNT interfere with the slide,I hope this doesnt sound confusing because its not hard to do.I think it allowed me to lean out the main one size,helped my gas mileage some,and going out of a corner allowed me to pull a taller gear,better smooth throttle response.Its been awhile so Im just going by what I remeber,dont expect miracles but for something you can do for free and a little time it was worth it.Its all the little things you do that add up to improved power/milage. I dont have the Moose spacer on my 500 (Im makeing my own)but my wife has one on her KX85 and it helped smooth out the "hit" and did help low/mid range,she doesnt ride enough for me to be sure if it helped gas milage(It did seem to a little),but its only $20.00 and from the post Ive read its worth it.Some of the mods Ive done a few at a time,so to be sure how much "bang for your buck" your getting do one at a time and log the results in a note pad.