67` Bomber running problems

[mo goldie]

Hi Everyone

Well anther Question .... I am having a problem with the left hand CARBURETTOR ?

it pops and bangs still on the over run and I have sorted it out somewhat but the mixture screw is only out Not even a half a turn..... and when you start it from cold the left Cylinder stays cold for a while so running on only the right which has No issues
so any Advice what it Might be ........ other than that it is going well 

   

[royhall]

Sounds like your carb balance is off. Tricky thing to sort on a bomber as there's no vacuum ports to connect gauges to. I have drilled mine into the alloy in front of the carbs and fitted permanent connectors with blanking caps but it's still tricky to set. Try raising the tick over on the left and lowering it on the right to even it out. Don't worry about the popping on overrun they all do that but getting the balance better will help stop it.

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[mo goldie]

Hi Roy

yes I have tried to do the right carb a bit less on tickover and more on the left but then when you Rev it up the tickover seem to come down to 2,000 rev`s for a while then come down to about 1,000........ i have been trying over the last few weeks to get it right..... Not far off now. but Not so much the popping Now but the first start up seems to be the problem.

Oh well I will keep going 

Oh the Spark plugs are running a nice shade of Brown so mixtures can`t be to bad ha 

[royhall]

I have found that it's almost impossible to set the carbs correctly even with ports and vacuum gauges. The tick-over pressures are a way off if you want stable running at 1000rpm. If I try to balance it  I get the exact same deal you described, slow getting back to tick-over speed. The pressures are fairly close at faster running. I'm beginning to suspect a problem with the air filters, after all they are (expensive) pattern parts so they are probably crap.  I also still have sooty black plugs (again could be air filters). I'm thinking of checking pressures with the filters off and maybe some free flowing pods. I'm getting close to ordering a Mikuni conversion to be honest as it's not really usable as it is. Still got the above things to try, plus the original 14C's to finish building and try yet. Need to buy some enthusiasm for doing it.

[mo goldie]

well it seems as tho i have not got a bad set up then with how she is running as you say the air filters are some what hard to get .... and cost too.. But what I done is was to cut away the old paper and I have used some proper Air Filter Sponge so that's why it might be running great with regards to the spark plugs being the right colour then. so maybe the way to go Roy to see if that get rid of your Richness running sorted ? so give that a go before Paying out for the Mikuni Carbs as I say mine is running good Now just the little problem but I can live with that.......and I have No flat spots too with the old 14C carbs