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sooty plugs

Posted: Wed Jun 13, 2012 9:48 pm
by lowride stepside
right its a 1275, 44 carb, k n N air filter, LcB manifold real short exhaust exiting sideways , electronic ignition , before iI fitted the overdrive the plugs where biscuit brown , but when wrestling the engine and box out and in again + the short stay in the wheel barrow the dizzy seemed to move way to advanced , with a bit a fiddling it runs lovely but my plugs are black weaken it down and it doesn't like the pedel I've got 10/40 in the dashpot and the needle had bda stamped on it (I think )
any ideas

Re: sooty plugs

Posted: Thu Jun 14, 2012 12:14 am
by bmcecosse
The normally suggested needle is the BDL - your BDA is slightly weaker at higher revs - so that won't be the problem. I can only suggest you make sure the 'choke' is going fully off - and have a look at the fuel level. Does the jet show obvious wear from the constant rubbing of the sprung needle? And make sure the needle is fitted correctly in the piston, and the piston can rise/fall easily in the bell. And try to advance the timing until you hear a little pinking -then take it back slightly.

Re: sooty plugs

Posted: Thu Jun 14, 2012 9:04 pm
by lowride stepside
like i say it was bicky brown before , so it surley couldn't of worn the jet , choke is deffinatly open , would advacing the ignition make that much differance ?
it's also got B8es plugs in and i think they should be B6es , tho the guy in the shop insisted on trying to sell me Bpr7es,and ive never had protruding electrodes and resistors fitted before . any recomendations ?
.shouldnt the needle be a richer one than standard with the filter and pipe and if so what would it have stamped on it ?
the piston goes up an down though there is a bit of hydrolic resistance due to the oil in the dashpot , ive tried thinner oil but it makes the carb cough :o

Re: sooty plugs

Posted: Thu Jun 14, 2012 9:15 pm
by bmcecosse
You would need a weaker needle to lighten up the plugs. I always use Champion plugs......after v annoying experience with NGK on a mates car. N6Y for me.......

Re: sooty plugs

Posted: Thu Jun 14, 2012 9:37 pm
by lowride stepside
So hotter plugs , it also runs on dieseling another sign of it being to rich would the plugs make a differance to this

Re: sooty plugs

Posted: Fri Jun 15, 2012 10:45 am
by bmcecosse
Yes - I think so. Worth checking if the needle is fitted completely flush to the piston - and do have a look at the jet.....

Re: sooty plugs

Posted: Fri Jun 15, 2012 7:33 pm
by lowride stepside
what If i went to a thinner needle increasing the richness of the mixture under acceleration without the carb coughing ,possibly enableing to use a lighter oil thus making the piston react quicker, allowing me to turn down the A/f mixture screw for the overall running . and if so does anyone know the order in which the needles go from poor to rich bda, bdl bla bla bla

Re: sooty plugs

Posted: Fri Jun 15, 2012 7:40 pm
by bmcecosse
You don't need a thinner needle - your plugs are already 'sooty'. Is there a spring in the carb - above the piston? Compare needles to your hearts content on mintylamb - but seriously - that's not the problem.

Re: sooty plugs

Posted: Fri Jun 15, 2012 10:30 pm
by lowride stepside
lamb stuffed with garlic Mmmm :o