all the plugs ive used are what handy bikes have said to use. i also used the plug that came with the bike and it had a bosh # on it , i took it to an auto parts store and the cross referenced that plug. i know theres many factors involved with an engine. with the ngk BR5HS im now getting a a slight brownish color on the white tip. on the others it always stayed super white. FROM 4OZ. OF OIL PER GAL DO YOU THINK I SHOULD DROP TO 3 1/2 OZ. ????????. I HAVE 2 KINETICS NEVER RUN - BRAND NEW AND TOM I GUESS HES THE OWNER SAID TO USE IN THESE BIKES 3 1/2 OZ. OIL PER GAL. THE BOOK SAYS 4 OZ. PER GAL. MY BROTHER HAS A 2003 KINETIC AND HE RUNS 4 OZ. OIL PER GAL. I SEE HE SMOKES QUITE A BIT WHEN HE TAKES OFF FROM A STOP. THANKS DOUG IN TX.