Re: you're favorite upgrade
I can tell you that by far the most absolutely effective, efficient, and most hp producing mod that you can do to these motors is to completely strip them down bare, and starting from a split bare case ............ grind down and de-bur everything, stuff the case halfs bearing bosses with jb weld and grind down for crank clearance, port match the jug to the case, reshim and stuff the crank balance holes, port the jug way wider (60% on the exhaust and as wide as you can on the intake) , corfect transfer port angle, DO NOT RAMP THE PISTON IT WILL MAKE YOUR SQUISH BAND INEFCECTIVE IN THE RAMPED SPOTS, deck jug to a near zero deck hight to allow for squish band clearance adjustment through head gasket thickness swaps,cut piston skirt for intake clearance and desired timing, deck the crap out of the stock head till its about 5.5cc then by hand grind a squish band into it and reshape the chamber to a conical dome, port match your intake amd extend it with a hose to 6 in length, rejet carb with drill bits and solder, port match exhaust and cut it open and tottaly gut it out and weld cap onto end, replace plug wire with nkg wire and nkg plug boot, install iridium plug, makes shure to debur slot in the clutch shaft and pack the clutch shaft and shaft hole with red bearing grease for ease of operation and tighten that damb clutch spring down tight cause you should be at 11:1 static compression now !!!!
if your feeling up to it weld up a custom exhaust spasificaly tunned to your new motors desired rpm power band or adapt a good wide band powerband x chamber like the stock ktm.
all of this can be done with nothing but a dremal tool and some bits, some jb weld stick, and a rubber hose and a soldering iron and drill bits with a bunch of sand paper ..... normal garage tools !!!
i garentie you that for only a few bucks and a whole lot of your time .... you can get more from this than any upgrade or aftermarket part there is in existance .
Last edited by rogergendron1; 05-27-2015 at 04:21 PM.