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Su carb needles withK&N air filters
Posted: Sat Dec 05, 2015 1:48 pm
by tractor boy
Hi its tractor boy just making a start on all the jobs that never got done during the summer. 1850 is off the the road for winter and i would like advice on the correct needle to fit in the su carbs now i have fitted K&N filters and stub stacks.The engine doesnt pickup cleanly until it has done 4/5 miles.All other settings ignition etc are spot on. I didnt change the needles when i fitted the air filters. THanks for you help.Tractor boy
Re: Su carb needles withK&N air filters
Posted: Sat Dec 05, 2015 1:54 pm
by Toledo Man
You'll need richer needles with K&N filters because the extra airflow will result in a weaker fuel/air mixture.
Re: Su carb needles withK&N air filters
Posted: Sat Dec 05, 2015 5:22 pm
by Jon Tilson
Bit simplistic is that Dave...
You need to set it up on a rolling road really to get the best. Or you can have a look at the Minty Lamb web site and his SU
needle comparison chart, which is great.
Dolly 1850's use ABK IIRC and I think you can see an ADH is a bit richer at the bottom. This was too much so for my spit 1500
so I ended up with ABK's in that, but these are weak on a dolly top end wise even on the standard air filter.
You can buy a lot of needles for the cost of a rolling road session, but it takes a lot of time...
Jonners
Hmmm.......
Posted: Sat Dec 05, 2015 6:33 pm
by sprint95m
I suggest fitting an original air box to see how it runs.
If you want to upgrade the air filter I suggest fitting an external conical type to the original air box (via a Y-piece).
Ian.