Motorcycle Repair: norton carburation, mechanical abilities, carburation

Question
i have a 75 norton 850. replaced amals when slides wore out w/ 34mm single mikuni. ran well for about 6 mos. then had problems w/ rust in gas tank. cleaned & sealed tank & carb. would not start w/ stock jets so i replaced w/ the largest jets that came w/ kit. now starts but will only run w/ choke on. i have limited mechanical abilities and this is really frustrating because this bike is so fun to ride w/ it runs well. thanks

Answer
Jeff
If the bike ran well with the new carb and the problems came about after the rust cleaning and sealing, then I would think that there must be some little piece of gunk somewhere interfering with your fuel supply.

Having to run with the choke on means that you are getting too much air for the available fuel, and have to compensate.

So my advice, as long as ALL other tune-up factors are correct, is to try another thorough cleaning throughout the fuel system. There is no telling where the problem may be located.

John