Yeoman Posted December 1, 2008 Share Posted December 1, 2008 Has anyone got a clue as to why the front plug should foul up after being in the bike for a week. The fouling indicates a rich mixture, but I don't even use the choke & the carbs haven't been touched. The bike is used for travelling to work (10 min. ride) but this problem has only just started, there is also backfiring through the exhaust & popping in the carb. Its got so bad that I'm considering taking it to a motorcycle garage to get it looked at. Any help in sorting this would be greatfully received. Link to comment Share on other sites More sharing options...
JimR Posted December 1, 2008 Share Posted December 1, 2008 Has anyone got a clue as to why the front plug should foul up after being in the bike for a week. The fouling indicates a rich mixture, but I don't even use the choke & the carbs haven't been touched. The bike is used for travelling to work (10 min. ride) but this problem has only just started, there is also backfiring through the exhaust & popping in the carb. Its got so bad that I'm considering taking it to a motorcycle garage to get it looked at. Any help in sorting this would be greatfully received. Hi there, just did one with the same fault last week (uk bike but it should be the same). Balance the carbs (with vaccum guages and adjust the 2 mixture screws located on the r/h side of the bike, they look like a tube just below the carb to covers. Method :- warm the motor and use the idle screw to get the bike to sort of idle at 1k ... it will be well doggy check the balance and adjust via the screw on the l/h side between the carbs, as adjustments are made the idle may need to be adjusted to get it back to 1k, once you have the v gauges reading the same open the throttle and let the bike return to idle & recheck the gauges (the bike may still be uneven & cutting out on the front cyl) ... now go to the mix screws (down those tubes) screw the screw anticlockwise until the revs rise (then do the same for the back cylinder) the idle may now be very high adjust it back to the 1k setting, allow the bike to idle & see if the cylinder cuts out. continue adjusting the mix screws in the above manner until you get a smooth idle, the only problem I had with my repair bike was the front mix screw was seized solid, took ages and lots of WD & gentle persuasion. let me know what goes on Regards Jim Link to comment Share on other sites More sharing options...
Yeoman Posted December 2, 2008 Author Share Posted December 2, 2008 Hi there, just did one with the same fault last week (uk bike but it should be the same). Balance the carbs (with vaccum guages and adjust the 2 mixture screws located on the r/h side of the bike, they look like a tube just below the carb to covers. Method :- warm the motor and use the idle screw to get the bike to sort of idle at 1k ... it will be well doggy check the balance and adjust via the screw on the l/h side between the carbs, as adjustments are made the idle may need to be adjusted to get it back to 1k, once you have the v gauges reading the same open the throttle and let the bike return to idle & recheck the gauges (the bike may still be uneven & cutting out on the front cyl) ... now go to the mix screws (down those tubes) screw the screw anticlockwise until the revs rise (then do the same for the back cylinder) the idle may now be very high adjust it back to the 1k setting, allow the bike to idle & see if the cylinder cuts out. continue adjusting the mix screws in the above manner until you get a smooth idle, the only problem I had with my repair bike was the front mix screw was seized solid, took ages and lots of WD & gentle persuasion. let me know what goes on Regards Jim Hi Jim Thanks for the advice, The mixture screws are free as I checked them last week (both are 1 3/4 turns out. Must admit I haven't balanced the carbs for a couple of years. Before I can play with the carbs I,ve got to get the thing going, no start this morning, plenty of juice in the battery, just not firing. Regards Greg Link to comment Share on other sites More sharing options...
JimR Posted December 2, 2008 Share Posted December 2, 2008 Hi Jim Thanks for the advice, The mixture screws are free as I checked them last week (both are 1 3/4 turns out. Must admit I haven't balanced the carbs for a couple of years. Before I can play with the carbs I,ve got to get the thing going, no start this morning, plenty of juice in the battery, just not firing. Regards Greg Hi Greg the screws could end up being 4 turns out and for sure they wont be the same setting I have now one set at 1 turn & the other at 4 ! if you have not checked the balance in that time how about valve clearence and cam chains ? as they should be checked b4 carb balance and mixture strength checks. With the non start issue test for a spark then go from there. Regards Jim Link to comment Share on other sites More sharing options...
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