Hi, I have a 1994 Beta Techno, the bike runs great, starts first kick but I am having loads of problems with it fouling a new spark plug after about 2 hours riding. The plug is very black and sooty when removed. I am running a BP5ES plug 70,1 fuel mix, i have replaced crank shaft oil seals, air filter spotless mixture screw 2 turns out Does anyone have any ideas as I am at my wits end with it. Thanks Alan also meant to say its got a delorotto carb a cf 262 main jet and a 65 pilot and the bolt holding the float bowl has a 88 jet in it (not sure what that jet in the bolt does as ive never came across it before can anyone help)