Re: Back firing

Posted by mikey440 on Aug 23, 2010; 1:41am
URL: http://vintage-and-classic-hondas.81.s1.nabble.com/Back-firing-tp1270157p1283094.html

 The 125 main jet is too big, ive got 102 in mine with 4 into 1 header and it runs fine, make sure your throttle cable is returning good, also sounds like a intake leak for the backfire, or the 125 mainjet is givin too much fuel and giving a flooded situation causing backfire, find which pipe is bacfiring and address that carb and change plugs, probably fouled, also turn idle mix screws out 2.5 to 3 turns from lightly seated.
 must use stock airbox for these carbs to work correctly, check timing although i doubt thats it, most of time on these bikes its the carbs, they have to be sparling clean, also check inline fuel filter for crap, if you dont have one, get one,,hope this helps, mykey440