Low-fuel sensor leaking gas...

[Xenithar]

On my 1981 550LTD I have developed a leak on the low-fuel sensor under the tank. There is a square, orange rubber piece that has become hard and leaks now. I cannot find the assembly to order a replacement. How can I fix this?

[MFolks]

Pictures? Tried Z1 Enterprises, Inc. - Quality New Parts for Vintage Japanese Street Motorcycles for parts?

[Xenithar]

I did check, but did not see one listed. Here are the pictures of the one out of my old fuel tank. The one in my current tank is very clean. Both of them have this problem though. The orange square piece can move a little and it leaks.
IMAG0407.jpg

[MFolks]

I suspect the orange block is part of the insulation for the sensor, and the Ethanol in gasoline has attacked it.

Ethanol In Gasoline Problems (E-10,E-15,E-20 &E-85)

Certain materials commonly used with gasoline may be incompatible with high-level ethanol blends, causing them to degrade and contaminate the fuel. Metals that have been shown to degrade over time in the presence of high-level alcohol blends include brass,(floats & jets) lead, zinc(carb bodies) and lead-based solder.

Nonmetallic materials that degrade when in contact with ethanol include natural rubber, polyurethane, cork gasket material, leather, polyvinyl chloride (PVC) polyamides, and certain thermoplastic or thermoset polymers.

On the other hand, unplated steel, nickel-plated steel, stainless steel, black iron and bronze have shown resistance to ethanol corrosion, with nonmetallic materials like reinforced fiberglass, Buna-N, Neoprene rubber, polypropylene, nitrile rubber, Viton and Teflon meeting acceptable usage standards with E85.

1. Ethanol can break down resins and fillers in fiberglass gas tanks, causing them to leak.

2. Resins leached from fiberglass tanks can go through the fuel system, sticking to valves and other internal engine parts.

3.These deposits have caused bent pushrods and have clogged intake valves.

4.The alcohol attracts water, leading to increased corrosion in metal gas tanks.

5.Water in the fuel affects the octane and leads to knocking and decreased performance.

6.Ethanol acts as an efficient solvent, gradually cleaning out the accumulated gunk in fuel tanks and lines, and clogging carburetors.

7. Certain rubber gaskets and fuel lines are weakened by ethanol. Some rubber fuel lines may develop internal swelling, restricting the flow of gasoline. My understanding is the Silicone fuel lines resist the effects of Ethanol in gas.

8. The Ethanol in the gas has been reported to attack the glue used in gas filters, rendering them useless, as the paper filter medium is now coated with glue. It also softened the filter hose connection ends, causing possible failure.

[martin-csr]

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[Xenithar]

I know that ethanol is the likely culprit, which is why I use pure gas in it, but the prior owner did not. I just want to fix the darn thing. My whole bike has been down for two weeks now and I am ****ed. I am seriously wondering if I can join a class-action suit against the EPA for this crap. I can't just go buy a replacement so it looks like my vintage bike is scrap due to a single rubber piece.

[martin-csr]

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[MFolks]

Yep, the EPA mandate has yet again screwed people over. The boat owners had it similar until they got an exemption to the E-gas, as it was dissolving their fiberglass fuel tanks, costing $$$$ for repairs.

[Xenithar]

I remember ethanol melting some boat tanks. That had to suck! I already tried sealing it but no go. I am so mad because until now, the bike was 100% original and 100% functional. I want my piece replaced to keep the value up. I think I will be filing a complaint with my local government. Hell, when E10 came out, nobody here bought it because most farmers knew rubber would break down with alcohol. What did our government do? They decided to start using E10 and not marking the pumps so it would sell. Sounds like an attack on my personal freedom. Yes, I am VERY angry right now. I prided myself on having an original bike.

[Xenithar]

I just wanted to update everybody on this issue. I used a very small amount of Marine-Tex around the orange piece on the top and bottom of the piece and it fixed the issue. It has been over a week now with no dampness or leaking. This stuff is AWESOME! Still have my original bike and I just bought the 700 LTD and can't wait to ride it!

[MFolks]

What type of adhesive/sealer did you use? Their website lists several varieties. This will be good news for other riders in your situation.