- Jan 7, 2002
this is for the experts a friend of mine has a 99 kx125 that is basicaly stock with stock jetting at sea level. the bike has good bottom for a 125 and good top for a 125 but just as the bike is about to hit powerband it loses power for a second or two and then goes into powerband and pulls fine all the way up. the bike runs storng off idle its just a small rpm range right before powerband that is the problem it doesn't compleatly bog out it just loses its power and lind of gurgles a little. the bike has a fresh top end, resent crank and when doing the top end the powervales operated very smoothly and seemed to have little carbon i tried moving the needle clip up and down one clip with no luck also tried one smaller size main and one bigger main but the bike runs best with the stock sizes i am thinking maybe something is wrong with the power jet but how to i check this? or does anybody else have any ideas? he doesn't have a lot of cash so i don't want to just start replacing parts unless i am sure it will make his bike run better. it really feels like there is a rich spot in the carberation right at that rpm would a bad power jet do this?