Skip to main content
English French German Italian Spanish

99 running rich.

Forums

My  single carb  376 with a light filter  persists on running rich  and sooting plugs.  Even the expensive fine wire ones.  And despite my best efforts they are not happy to be cleaned  as the soft ceramic insulators are now not glazed and soak up any oily soot .  The mixture screw needs to be 3 turns out to keep  the mixture somewhere close. I think I will have to try a 20 pilot jet, does anyone use a 20 on a dommy.?.  Have not seen any recommendations  on jetting changes with a filter.I am also using Esso top grade to avoid the eth issues  and I think that also tends to make for richer  running.

Permalink

Hi Ian, On this model to get the filter out is a pig.  Remove side panel ,remove battery ,reposition wiring. unbolt filter cover unbolt filter box studs,and battery tray ,wiggle box and glued in filter thro forest of wires ,replace battery carrier and electrics to try out.The reason I won't run without a filter is these models have poor internal mudguarding  and throw a lot of  dirt at the carb area . Putting the poorly made  box back is a major fiddle with the rubber connector fighting you . Best unbolt oil tank and lean away for room. No thanks .

Permalink

Rechecked your float height? I know you have done mods to the needle valve area, but is the fuel level still 'on the dot'?

You may recall my 650 was running like a pig (very rich at and just off idle) last year after the rebuild,  and it turned out to be the float not shutting off properly. In my case Amal stayup was more like staydown.

In my case, an extra float chamber gasket 'resolved' the issue completely. Worth checking before you tear your hair out completely!

Regards, George. 

Permalink

Hi George, The weird thing is I can go from sooty plugs to spitting back off idle ,then for a few months all is well and I have a slow even tickover to die for.  It may come to a new carb. I went back to a brass float after sticking games with plastic.    **** light bulb moment,   its the bloody fuel,  no  .consistency    ,the last purchase  was a tank full of genuine  Synergy plus.  Previous purchase was  EO5   in the Synergy  pump  and I adjusted for that. Thieving gits.

 



© 2024 Norton Owners Club Website by 2Toucans