Running erratically

kommando said:

If no choke is fitted then if it starts well and once its up to temp it also runs well, then its too be expected as it warms up it needs babying. There is no ECU to keep the mixture correct at all temps. So you tickle the carbs before starting to get a rich mixture by raising the fuel level in the float which you have right as it starts well. Then as the engine warms up the fuel level is also dropping and leaning out the mixture, if it leans out too quickly then the engine will falter, too slowly and the same will happen as the mixture will instead be too rich.

So next time you start the bike, tickle the normal amount and then as it starts to miss tickle for a second time. If it improves then the mix is lean, if it gets worse then the mix is too rich.

If the mix is lean then in future either tickle twice or fit a choke, too rich then apply some throttle for a min or so and live with it.

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ashman said:

1 1/2 turns is just a start for adjustment, each carb should have a final tune with the air mixture screws to get each carb set right and each carb can be set differently to each other, set the air mixtures with the motor at running temp, read up on how to tune your carbs, its not that hard, I always set them pretty close, then take a ride and carry a small screw driver to make minor adjustment while out if need to change the settings.
Jets can wear oval after time and the O rings for the air and idle screws also wear from age, when my Norton was an everyday rider I replace needles, jets, O rings every 2/3 years, Amal carby kits are cheap for keeping your bike running great, all part of long term general maintenance.
But as said if the bike has been sitting for a long time of course all fluids should be changed, a good charged up battery also a good idea to pull the carbs down and give everything a good clean, old stale fuel turns to crud if left sitting in the carbs long enough and don't assume its carb problem, could also be electrical causing the problem.
Of course any smart person would go over the whole bike before riding it if it sat for a long time.

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