coaster enricher

Gents
can someone tell me in basic terms what the coaster enricher circuit does on the carbs, does it make a lot of difference to the running?
many thanks

Paul, this will get you started.

Searched on keyword 'enrich' and member 'scotch'

www.kz1300.com/forum/daily-chatter/3898-sparkplugs?start=0

"The  point to my suggestion is that every time you back off the throttle - especially from higher RPM's  - the higher vacuum created in the intake manifold closes off a metered portion of "Mixing-Air" supplied by the enricher system.... proportional to the level of vacuum..  Less mixing-air.....richer fuel mixture. Under normal riding the enricher spring keeps the piston open and the correct proportion of air is maintained. 
So in a simple and relatively easy process of elimination of helping determine the cause of the sooty plugs, I make the suggestion. 
I did this two years ago and haven't had any backfiring and got a (albeit modest) but otherwise noticeable and recordable increase in K.P.L. (M.P.G.)  "

"but for some reason 3 and 4 are running rich and I can't get the flame blue enough... the screw on those is also very hard to reach.

Apply some air pressure to the Mixing-Air ports  on the filter side.  This may clean out anything in them that's affecting the mixture adjustment. Applied PSI will not rupture anything !  
My "better" hunch is that the Enrichment piston is stuck in the closed position. I've seen these so "crudded-up", they'd barely move.  My option a year ago was to remove the diaphragms/pistons completely. You just have to make some simple solid gaskets for under the cover. This, along with a "tweak" on the ignition timing, a mod. to the pilot needles and an accurate "sync" gave me a significant increase in mileage with no adverse effects.
As for the pilot needles on the center carb .........convert them to a socket head. I've covered this several times.....if you look for it.  You'll kick your ass for not doing this right from the get-go!"

 

Thanks very much ill give that a go

I'm interested too. I have intermittent lean to rich and thinking it might be 'sticky enricheners'

A friend of mine has just been through my carbs, taken them completely apart and ultrasonically cleaned them etc and apparently all three of mine were f#cked so he replaced them.
In the past i have successfully cleaned my carbs to a standard that they we were running fine but this time i struggled with various issues so sent them to him as he has more time, knowledge and also the right equipment but i have never touched the coaster enrichers before but from what i can make of the info available the only purpose it physically serves is to stop any back firing when you back off the throttle and has no effect on the idling or start up but in fairness my knowledge of carbs is basic at best.