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Can anyone tell me what advantage there is to blocking the high speed jets? My last set of carbs had this done, but the set I have on at present does not. Also do you need to alter anything else once they are blocked ie. jet sizes?

Cheers

from what i understand is, its easier to get them setup on the dyno with a ramair setup when they are blocked. Id imagine on a fully tuned motor without blocking the air correctors, you would need very big mains...which may lead to other problems coming off the needle?
im not sure tho

You must block off the main air jets with Ram air - The carbs otherwise have fuel blown by the high speed air on a closed throttle. This will empty the float bowls.Once the throttle is fully opened again, the float bowls can't fill fast enough again, and you will get a extremely large hole / flat spot during which the engine will run far too lean, with all the consequences that go with it. The flat spot is so significant that the engine will baulk for about 2 seconds before it starts to pull again.
I struggled with 120 and 125 mains for 3 or 4 runs ( which with open main air jets actually ( and confusingly) means the bike is jetted perfectly at the top end - 14500rpm plus),but once the main air is blocked the flat spot dissapears and you go down to about 110 main, which means you carry / use a lot less fuel. I wouldn't even consider not blocking the main air. I should also say that I have a quick throttle, so perhaps if you were gentle with the throttle openings, the problem might be masked to a certain extent. I know Dynojet block them with araldite.

hi could you tell me if your info is for flat slide carbs and where would i find the air correction jets thanks