Re: What is a VST and do I have one?
Its a fuel filter mounted on your engine before your injectors.Another forum I'm on has a Yamaha mechanic that says it should be replaced every year. This is what he had to say.
"The main issue with VST filters is with people who dont use their boats on a regular basis. When not used, the area at the top of the VST (on the inside) which is wet with fuel when you first shut off your motor; soon dries off after your engine sits for a few minutes. This is where ethanol causes problems Its not where the fuel IS, its where the fuel WAS. Ethanol leaves a white chalky residue on aluminum (VST) after the fuel dries off. Next time you start your motor, that chalky residue gets hit with fresh fuel via your mechanical lift pump. That chalky residue now falls down to the bottom of the VST, and mixes with the fuel. This is what your Racor CANNOT filter. This fuel has already passed through your entire boat fuel system.
It has two more stops before it enters the combustion cycle. First is your VST filter. After that is your fuel injectors, which also have individual filters. VST filters are inexpensive (when compared) and easy to change. Prolonging changing VST filters, greaters your chances for clogged injectors, stuck injectors, and dirt injector filters. All of which are very pricey to have serviced, and cannot be serviced by yourself, or your average marina. Injectors have to be sent out to companies with the proper machines to that service/clean them."
Hope this helps you.
