Hi Guys:
Having some problems here on a 2003 B-12 after Dale's stage 1 kit instal and would appreciate any ideas.
Settings were (Stage 1 kit)
5 shims
110 mains
Stock pilot jets
Air box mod as per kit
Pilot screws 3 ½ turns out.
Experiencing rough idle with “coughing” at low rpm 1500 to 3000 rpm. Bike is very smooth in the higher rpm ranges with no hesitation at all after 3000 rpm.
We took the plugs out of the bike and found 1, 2, & 3 plugs in excellent shape with the 4th sooty. Re-checked the air screw adjustments and the 4th carb may have been have been set out just a bit more than the others but I would stress that the other plugs were in such good shape, I find it hard to believe that the minor difference could have fouled that #4 plug.
We replaced all the plugs, set the screws to 3 ½ turns out and re-synced the carbs. Syncing the carbs seemed touchier than I remember.
Still experienced the slightly surging idle and coughing while in 2nd gear at about 2000 rpm.
Played with the air screws. Set them out to 4 turns and it appears that the coughing got worse at low rpm and on the test ride adding a little choke seemed to make things worse.
While the bike was running it seems that the further I turned in any air screws the better things ran. Currently we have them set at 3 turns out which we saw an improvement with the condition mentioned but it is not perfect.
Of course the #4 cylinder is suspect. Other than a poorly set float, what else could have cause this plug to fail? Loosing one of the small O rings? Or perhaps a badly seated spring?
As suggested Simon will put a few miles on and we will have a look at the plugs again. If #4 is sooty again on inspection I would suggest that something went wrong with assembly of the #4 carb perhaps?
As mentioned, the 1,2 & 3 plugs looked fine with the screws set to 3.5 turns out so logic would say that should be the number to use. (We will know more when we look at the new plugs after a few miles) I think we may now have the bike running lean on the 1st 3 cylinders to make up for the 4th running rich, but it does run better here.
The more I think about it, #4 carb must be the problem. If we look at the 4th plug this weekend after a few miles and it is not sooty. I would like to know what the minimum turns out stage 1 kit. Can we go to 2 turns out. (From what I can remember most run with 3.5 turns out on the stage 1 kit and the plugs that we saw on the 1,2 & 3 cylinders would agree.