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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. :lol: 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!