ba baraccus Posted June 13, 2005 Report Share Posted June 13, 2005 We are having difficulty with my mates bike, it seems to foul up plugs a lot (very black)! Its a Fantic 309 so I presume getting the correct jetting info may be hard so I was wondering if you guys had any tips? Is it worth dropping the needle and adjusting the air/fuel screw? If so by how much?? Any ideas guys? Quote Link to comment Share on other sites More sharing options...
alan bechard Posted June 13, 2005 Report Share Posted June 13, 2005 Start at basics, Clean gas, proper oil ratio, clean air filter, new correct plug etc. etc. Then tune / jet from there. All too often we miss these basic steps and go past what the actual problem is. Quote Link to comment Share on other sites More sharing options...
ba baraccus Posted June 13, 2005 Author Report Share Posted June 13, 2005 Thanks Alan! We have drained the tank and put in fresh gas (we are mixing at 100cc to 5 litres) and my buddy is getting a couple of new plugs so we are ok so far but it did foul up a new plug yesterday so we thought it may now be down to jetting?? Quote Link to comment Share on other sites More sharing options...
jools Posted June 13, 2005 Report Share Posted June 13, 2005 It will be if your not using too much oil. Running too rich. Check air screw adjustments, failing that, jetting. Quote Link to comment Share on other sites More sharing options...
charliechitlins Posted June 13, 2005 Report Share Posted June 13, 2005 And if it used to run well, it can't be jetting. Those little holes in those little brass thingies seldom get bigger Quote Link to comment Share on other sites More sharing options...
jtt Posted June 14, 2005 Report Share Posted June 14, 2005 Could be crank seal too, sucking gearbox oil. Perhaps ignition is weak. Lots of possibilities, but like Alan said, start at the basics and work your way forward, making no assumptions. Quote Link to comment Share on other sites More sharing options...
ba baraccus Posted June 14, 2005 Author Report Share Posted June 14, 2005 Thanks everyone that should give us something to go on for a bit Quote Link to comment Share on other sites More sharing options...
grib Posted June 14, 2005 Report Share Posted June 14, 2005 Those little holes in those little brass thingies seldom get bigger Not true! It won't happen suddenly but a 309 is going to be 13-14 years old. I have got a 301 which was fouling plugs very quickly, changing the needle & needle jet for new ones (of the same size) stopped the fouling but also leaned things off so much that it started to pink & I had to raise the needle a notch. Quote Link to comment Share on other sites More sharing options...
betamike Posted June 14, 2005 Report Share Posted June 14, 2005 try running the bike with a dry air filter or a filter with very little oil if you dont fancy that.i own a 94 kroo it used to do that but did what bill pye said and it worked.good luck. Quote Link to comment Share on other sites More sharing options...
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