su carb running too rich

[morris minor man]

hi i have bought a brand new nos su carb..bought it in the box ..and fitted it to a 1098 morris minor the needle is a an and the jet is a aud 9098 jet..iv set the mixture to 12 flats..and its too rich..from the front of the car im turning it anti clock wise.but its doing nothing..i dont know how many turns iv done now iv lost count..but it will not weaken...its so rich that when i pull the choke out ..it cuts out...some one has had a look and says its a air leak thats sending the carb rich???does any one know what can be wrong with it...please

[kennatt]

disconect the choke to eliminate,then screw the nut right in and push the jet holder up so that you know it is fully in and start again . An air leak would obviously make it weaker,but could effect the correct setting,check that the carb is seated to eliminate.

[mike.perry]

Have you put oil in the damper? Is the piston dropping on to the bridge? Is the distributor timing set correctly?
Mark one flat with Tipex or similar so that you can keep a check. Set the mixture nut at 2 complete turns down from the top and start the engine using the minimum choke necessary. When the engine has reached operating temperature adjust the mixture nut up or down a flat at a time until you get the smoothest tickover

[bmcecosse]

Does the carb have the correct float bowl angle for use on a Minor? If you switch on - and don't start the engine - does the fuel pump tick continuously? As pointed out above - an air leak cannot make the engine rich!!!!!! Run the adjustment nut upwards to weaken the mix - not down..... And is the air filter NEW ?

[mike.perry]

If all else fails - Read the instructions !!!!!!!!!!!!!!!!

[MarkyB]

How deep did you fit the needle?
I think the shoulder on the needle should be at the level of the damper.
Any higher that this will lead to rich running.