Your banshee 350 starts then dies the airscrews are 2 an1 half turns out you changed the gas new spark plugs cleaned the carbs and filters pulled the plugs and there wet with gas but you get spark?

It sounds like it is flooding.Did you check your float levels and needle valves and seats? Make sure the 2 floats in each carbie are both at exactly the same level as each other. I got the correct height on mine by using a vernier guage, alternatively you can make up a tool or buy one. Make sure there is no dirt under the needle valve. If you don't have a workshop manual go to your local reference library and photocopy the pages you need. Use the A3 setting on the copier it's better value if they charge.