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Mixture
Posted: Fri Sep 21, 2012 11:45 am
by lee_rob
Ok so I changed the air filter on the moggy to a K&N to allow it to breath a bit better, however this seems to have weakened the mixture presumably due to the increased airflow. So I adjusted the mixture until I got a smooth idle, this however meant It was very poor at pickup and no matter how I changed the mixture the plugs looked very weak. I changed the needle to a rich H6 needle and initially this seemed to help with better acceleration and pull in the gears. Slight problem is now I think shes running a bit rich as the exhaust sounds uneven and splashy and smells very fuely.
Anyone had any experience with using a K&N filter and which needle to use? Its a standard 1098.
Re: Mixture
Posted: Fri Sep 21, 2012 12:51 pm
by bmcecosse
Changing the filter should only affect hard running mixture. The original filter could easily pass air when idling/low revs - unless it was horribly blocked of course. You don't say what carb you are running? I the mix is rich (black plugs??) then turn the nut upwards!
Re: Mixture
Posted: Fri Sep 21, 2012 10:08 pm
by JOWETTJAVELIN
Go back to the standard filter which the manufacturer specified.
A K&N filter is simply 'bling'.
Re: Mixture
Posted: Fri Sep 21, 2012 11:31 pm
by Fingolfin
I've got a K&N filter and the mixture is fine! Or at least it
was before I rebuilt the carburetor.

Still, though, considering you've had such bad luck since fitting it, I'd think about switching back. If the mixture's so weak, it won't take advantage of the better breathing anyway.
Re: Mixture
Posted: Sat Sep 22, 2012 10:19 pm
by daveyl
I've fitted a K&N before and found the mixture needed to be adjusted. On another note If you have removed the carb or manifold recently, I would recommend that you check for air leaks. Re-tighten the retaining nuts and any vacuum pipes etc.
I say this because recently I had an issue with the engine taking an age for it to run properly from start-up before I could retract the choke. AND also for it to 'miss a beat' at high revs.
At first I thought it was mixture and then ignition. Took several frustrating weeks to work it out!