My recently acquired carbed motorcycle sat for 1-1.5 or so years before I acquired, no rust in tank. So far, I have used techron and a small dose of Stabil(red One) and on my 3rd(or maybe 4th) refill of gas tank.
So far, it's starting on 1st try, no other running or performance issues. Would hate to pull carbs, hence trying to ensure I take care of any future issues now.
Have B12 laying around, but have read it can destroy rubber seals or rubber components, so maybe not a good idea for motorcycles? Is it a myth?
Should I continue to use small doses of techron or switch between techron or B12 for each gas tank for 2-3 more gas tanks, before I put her to sleep for winter?
Any other advice or suggestions? Thanks very much
P.S: Have used Seafoam in the past, but that thing is expensive and I don't have any on hand, so rather avoid it 

