MMO is a shot in the dark.
It isn't going to dissolve rust or solid crystals that I've seen in fuel
tanks and blocking filters.
I'd replace the filter, but first I'd run the tank near dry and drain the
bottom 1.5 gallons of gas out with a siphon or pump and try starting with
all fresh gas. Put driver side front wheel up about 6" either with a jack or
on a curb and you'll be able to get most of the old fuel out.
I used a 3/8 rubber hose with solder wrapped around the end for weight.
pushed the hose down the tank, wrapped the hose with a rag at the filler and
blew compressed air into the tank.
I got lots of crystals about the size of bacon bits by using the pressure.
You can also blow air (compressed or your breath) back into the out pipe on
your tank and clear the filter sock.

Stan

----- Original Message -----
From: "Jason Kirk" <Gojira@ADELPHIA.NET>
To: <vanagon@GERRY.VANAGON.COM>
Sent: Friday, May 14, 2004 5:59 PM
Subject: Re: Marvel Mystery Oil

> Thank you to those who have replied to my original inquiry. Actually, it
was
> just Stan. Thanks Stan. I also want to clarify my original question about
> adding this "oil" to the fuel system. If one has a fuel system that is
> displaying symptoms of being dirty (surging under acceleration - suspect
> clogged filter), would this additive work sufficiently under these
> conditions? Or should the filter be replaced before using the additive?
And
> if replaced before, would I need to replace it afterward?
>
> Jason
> ("87 Weekender - California)
>
> ----- Original Message -----
> From: "Jason Kirk" <Gojira@ADELPHIA.NET>
> To: <vanagon@GERRY.VANAGON.COM>
> Sent: Friday, May 14, 2004 1:10 PM
> Subject: Marvel Mystery Oil
>
>
> Wasn't that a Beatles tune? Is it necessary to change your motor oil after
> using this product? And when using it to clean your fuel system, should
you
> change the fuel filter before or after the process? Thank you all.
>
> Jason