Concentric carb
Posted: Fri Aug 24, 2018 9:48 am
Does anyone know what the best working spec would be for an Amal concentric carb for a 50's G80? I know the correct carb should be a monobloc for my year but I've been having a lot of grief with this setup and I'd like to try something else.
Basically, I bought a new monobloc last year from Amal and have never been able to sort the slow running. Tickover's also a bit rubbish but the worst bit is just coming off throttle closed position when the bike surges and feels like its missing or 8 stroking. I've stripped and cleaned the carb twice and replace the pilot jet and tried a 3 cutaway slide instead of the supplied 3.5. I also found that the carb jet body had been poorly manufactured as the two air inlet holes in the jet body didn't line up with the holes in the carb body; fixing this and the other changes improved things from the position I started with when the bike was an absolute beggar to start but I've now lost patience with the existing carb. I've even been tempted to go down the Mikuni route.
Basically, I bought a new monobloc last year from Amal and have never been able to sort the slow running. Tickover's also a bit rubbish but the worst bit is just coming off throttle closed position when the bike surges and feels like its missing or 8 stroking. I've stripped and cleaned the carb twice and replace the pilot jet and tried a 3 cutaway slide instead of the supplied 3.5. I also found that the carb jet body had been poorly manufactured as the two air inlet holes in the jet body didn't line up with the holes in the carb body; fixing this and the other changes improved things from the position I started with when the bike was an absolute beggar to start but I've now lost patience with the existing carb. I've even been tempted to go down the Mikuni route.