How, just by looking at the spin-on fuel filter/canister, can you determine it looks good?If it's 2 years old, it needs changing, regardless.You could have crap in the carburetor.It takes only one small particle to cause problems.Sometimes, there will be no apparent problem just idling in the driveway,but putting it under a load will cause the problem.

You can replace that filter, put a kit in the carb,or have it done, and take the tank to a good radiator shop for boiling it out.Seal the tank afterwards.Check out this recent post from Axracer over in the the 48-60 Forum:

" If you want to keep the in cab tank and are concerned about leaks, fumes, etc., temporarily remove the tank, flush the insides (search on gas tank cleaning for methods) and coat the inside with aviation grade gas tank sealer, often called "slushing compound" for it's application method. Pour it in, slosh it all around to coat, pour out the excess and let dry. It's required on airplanes that use gasoline. You can find it at local airports that have private plane maintenance service, custom motorcycle shops (used to seal handmade custom gas tanks) and from Eastwood. New gas tanks are going to be made from much thinner metal."


Finally, after 50 years,why not just replace the fuel lines?They're not expensive.If you do all these things,you'll likely not have to do it again for 20 years.