fuel filter for gravity feed models

[fjfool]

as i go thru this bike i picked up in October, i am dealing with more and more issues that the previous owner was not honest with me about(so be it, i bought a bike without seeing it in person just on the sellers word-it is buyer beware so i will deal with it)
one i am looking at is the disaster of the interior of the fuel tank;
lots of water got in there, ans some pretty thick oxidation, kinda scaly/flakey
i am thinking: pull the fuelcock and the gauge sending unit(can i remove the sending unit?) make block off plates for the 2 openings, put about 5lbs of sheetrock screws and a quart of wd40 in there, attach it to the bbq rotisserie and let her tumble for the weekend.
i have had ok luck with this in the past
any other methods would be appreciated
my larger concern is the stuff that i miss that comes off later, i would like to filter that out before it clogs a jet
i purchased an under the tank yamaha filter from RPM, to later realize that it is for the later fuel pump models
i cant be the only one that wants to run a filter on their gravity feed bikes, how and where do you fit one?
as always, thanks for the help!

[FJ1100mjk]

It has been noted here by a few gravity-fed FJ owners, that a fuel filter on them is a no-no. It has to do with flow, or lack thereof when a filter is employed. This may, or may not be a hard fast rule. Perhaps others have successfully used a filter, so they can relate. I do not use (or ever have) a filter on any of my gravity-fed FJs.

Regarding fuel tank rust removal... I have used something called Rustol from Sudco with great success on three or four tanks. I have read that Yamaha now markets a rust neutralizer kit. Here's a place that sells it, but maybe you can purchase it locally if you think it's worth a try:

http://www.cumberlandcyclesmd.com/catalog_product_detail.asp?cat_8398-4209-100492_product_1474459.Yamalube174_Fuel_Tank_Rust_.htm

[giantkiller]

Yes I don't have a rust issue. But my bike was put away 10+ years in a constantly heated garage. With a full tank of gas. And when I got it the tank was empty. Major varnish. Still cloggs my carbs after several cleanings. And 2 full years of riding. I used a filter initially. And could only get about 2 gallons out before it would run out of gas and put me on the side of the road. I thought it was because of the manual petcock and the plate I had fabbed just wasn't letting me empty the tank. Until the first east coast fall rally. When everyone kept telling me it was the filter. "Take it off" I didn't believe them. They kept saying it.

So I finally took it off to try it out before the 12 hr ride home. And I ran 5 gallons out before turning the manual petcock to reserve.

I still have to take the carbs off to clean them all the time. I purchased all the parts (including the aftermarket safety switch) to convert the 86 to a fuel pump. So I can run a filter. Hopefully will get it and all the other projects I have done this winter.

[red]

as i go thru this bike i picked up in October, i am dealing with more and more issues that the previous owner was not honest with me about.  one i am looking at is the disaster of the interior of the fuel tank; lots of water got in there, ans some pretty thick oxidation, kinda scaly/flakey
i am thinking: pull the fuelcock and the gauge sending unit(can i remove the sending unit?) make block off plates for the 2 openings, put about 5lbs of sheetrock screws and a quart of wd40 in there, attach it to the bbq rotisserie and let her tumble for the weekend.  i have had ok luck with this in the past.  any other methods would be appreciated. my larger concern is the stuff that i miss that comes off later, i would like to filter that out before it clogs a jet.  i purchased an under the tank yamaha filter from RPM, to later realize that it is for the later fuel pump models
i cant be the only one that wants to run a filter on their gravity feed bikes, how and where do you fit one? as always, thanks for the help!

Eric,

Your cleaning method sounds good enough.  Once the tank is fairly clean inside, you can remove the remaining rust using electricity:

http://www.stovebolt.com/techtips/rust/electrolytic_derusting.htm

After the cleaning, there are specialized gas tank anti-rust sealants that you can use, to protect the inside of the tank.  Red Kote gets a lot of good voting from riders, but I have not used it.  Other riders may have suggestions for similar products:

http://damonq.com/red-kote.html

You can help keep rust out of the carbs with a strong magnet.  This winter, I plan to gut out a clear, rebuildable glass filter, and install a neodymium magnet inside.  Fuel will flow normally, but rust will stop at the magnet.

Cheers,
Red

[Pat Conlon]

....put about 5lbs of sheetrock screws and a quart of wd40 in there, attach it to the bbq rotisserie and let her tumble for the weekend.
i have had ok luck with this in the past

I would like to learn more about this^^^
You must have one hell of a BBQ rotisserie motor to be able to turn that weight.
How are you going to balance the FJ's tank on the shaft?
With tanks off a backbone type frame, I could see this work....With the FJ's perimeter frame, I'm not too sure about the FJ's tank

I would go the chemical route for cleaning...and yes, no filter on the gravity flow fuel system although an inline screen filter is fine...no paper filters.

[movenon]

The FJ tank is the hardest tank I have ever had to clean. It's design doesn't lend it's self to cleaning. I smiled when the 5lb of sheet rock screws was mentioned. Getting those screws out is not as easy as some might think.  I had a few in the mix of bolt. nuts etc. in my first go at it.  Those screws get jammed in down in the "wing" area at the bottom of the tank (left and right side). And you can't see them.  Took a while time to get them out. I used a magnet and that helped but some were really jambed in.  There are areas of the tank that you can not see to inspect even with an inspection mirror.  One of those inspection scopes would have been handy. "Tankoscomey" so to speak.

I did the mechanical nut and bolt deal, vinegar, hot water, more vinegar, lots more pressurized water, Evaporust, more water etc. I worked on the tank for 6 or 7 days. As the tank's exterior was pristine I took great care not to mess up the paint.  IMO the pressurized water did the most to blow out the crap. I kept the process up until clear water flowed out then used the Evaporust, some Rust-Mort treatment dried with compressed air, shot some WD-40 in the tank. Once clean and dry immediately took the tank up and topped the fuel. I was concerned about small crap to I adapted a Fram G12 filter in the line because it was large and the case was clear so I could inspect it. I inspected it after a few hundred miles, no problem, again at 500 miles no problem and again at 1000 miles. Still clean. This spring I will reinstall a stock filter and call it done.

As a note I do not recommend the Fram G12 filter.  It is really to large to mount under the tank, I had to mod the mount a little and it is my opinion that the clear case plastic is not designed to withstand the amount of heat that is generated from the engine.  I have not had a problem but I am flirting with danger.  I will go back to a stock Yamaha filter. My bike is a 1990 with fuel pump.

No one or easy way to clean an FJ tank. Also just for information there is approximately a pint +- of fuel in the tank that is unusable, it is below the screen filter in the tank, down in those wing area's. That area is where any solid debris (crap or heavy rust particles) will fall and settle into. My theory is if any FJ tank develops a tank leak from corrosion that is where it will probably be. That is why you really don't want screws to stick in there to help things along.

Sorry for the long post, just forwarding some of my experience in cleaning an FJ tank. Not a fun job...
George

[Mark Olson]

Do not put a filter on a gravity feed fj,, you will starve the carbs at speed.

I prefer to use stainless steel nuts and solvent , then shake the hell out of the tank like a maraca.

you can't use a magnet to get em out but they won't rust.

then use a rust neutralizer and you are all set.

sometimes a float will stick open on the needle , when it does tap with a wood tool for shock value or ride the bike off a couple of curbs or speed bumps . 

[red]

Eric,

I heard of one rider who used a length of skinny dog-chain inside the tank as a cleaner, instead of screws or other hardware.  The good news is, it won't dig into narrow spaces and get stuck there as hardware might.  The bad news is, it won't dig into the narrow spaces as aggressively.  The guy used chain because once a single link came out, then they all came out.

Keep us posted . . .