I'm going to agree with @Seņor Gar on not running a pre-filter-filter on the fuel line. There's already enough stuff crammed in there and adding 3 potential points of failure above a hot engine and exhaust is not a good idea. The Type-B filter should be sufficient, just pull the fuel pump out every 10 years and clean it.
It appears the inside of the tank is not coated with a long-term protective coating, if it was the coating would be breaking down in more places than the weld seams, although that could indeed be the start of the breakdown. Instead it seems there is some chemical issue with the fuel and the many things that get mixed into a weld, noting welds aren't done if a vacuum.
The fuel is still an issue. Premium fuel doesn't have Ethanol
, which is the cause of many, many problems. However, after running tests with premium fuel and checking out the insides of the cylinders, I can confirm that on my bike (which ran somewhat rich instead of lean) Premium fuel was not
a good idea, as it did indeed not burn as completely as Regular and led to carbon deposits.
Buying Top-Tier gasoline
of the octane rating suggested by the Owner's Manual is the better option.
It was mentioned in many other threads, running SeaFoam is a good idea to keep things running well given the Ethanol issues. It was also pointed out that a SeaFoam substitute can be made at home, and I've since found a really great explanation with a better tested formula
Before working on the fuel system, PLEASE SEE THIS THREAD:
Removed the fuel tank