Hey all i have an annoying missfire on my 1.7 340 with solex carb.its across the entire rev range on part or light throttle .
If i keep the revs at a set rpm like say 2500 its misses in rhythm . Also struggles to idle after reving . The engine splutters and coughs .
Another thing ive noticed is on the overun there is a pop and bang from the exhaust about 3or 4 of them as the revs fall .

So far ive rebiult the carb with new gaskets , fliat, and followed settings from haynes etc.

This made the car loads better as it umsed to cut out round corners and wouldnt idle unless you gave it some throttle.

Yesterday i changed the dizzy and rotor and plugs, these were totaly goosed now the car seems eager to rev and crisper but still missfire etc.

Ive tightened the carb down as much as I dare . Looked for split hoses at the back of the carb . Still no improvement. Also tried sprayin wd around the base of the carb , there was no change in engine note whatsoever.

Things im going to change soon , new leads , maybe coil . Check valve clearance . Adjust co2 mixture .

It sounds like the idle solenoid (my favorite subject) - sorry, I can't remember if I suggested that before. Does it click when you connect it to the battery?

adjusting the mixture (by CO) should be done with the haynes setings, doing this will usually tell you if you have any mixture problems to start with.

Bogbasic , I hav'nt checked the solenoid . But when the car is on idle if i pull the connecter off the car cuts out . So ipresume its working . Although i could be wrong .

Ride-on im not sure what you mean ive read the haynes albeit quickly and cant see any sort of guide for the co2 mixture unless i have a afr device.

Its not really afr but yes you do need a measurement CO meter or colour tune.