Fuel Tap Leak

C

cinquecento

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Despite trying to lap the tapered end of the spigot into the mating surface on the tap using oil and fine grinding paste mix there is still a leak , all be it only amounting to a thimble full over several days.

Is tooth paste any use as a grinding paste to acheive a tighter fit, or should i just replace the tap?

Ta'
 
greg brillus

greg brillus

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It's probably easier to change the tap, but just check that the leak is not coming from the thread/nut sealing washer above where it screws into the tank. I have often found that a leak from a tap is actually from the tap to tank thread. If you blow the area dry with compressed air, and then look quickly you will see it. Good luck.......Greg.
 
Howard

Howard

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Toothpaste used to be made with very fine sand, so it would probably have been ok as a grinding paste, but I don't know what it's made from now. A friend of mine used to rally Minis in the 60s and used to use toothpaste to clean the windscreen - sand for dead flies and soap for grease.
I assume this is well known, but a friend's father was in the RAF during the war, and he used Brasso to clean fine scratches out of Perspex screens - an even finer abrasive.

H
 
C

chankly bore

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Yep, toothpaste,(the cheap white stuff) is great for lapping brass components such as float needles and taper type petrol taps. As Greg says, use lots of PTFE tape on both threads of the tap. Composite Viton? and aluminium washers available from the Club Spares may also be an improvement on the original fibre type. Make sure the mating face on the tank is flat by dressing with a fine file if nothing else cures the leak. Remember fuel can "leak" upwards as well as the normal gravity inspired direction. If you use mint toothpaste it may add an exotic aroma to your exhaust fumes- they once used mint in a brand of cigarettes, "KOOL" for memory. If I have mis-read your Thread then olive oil is good for soaking cork type plungers and the Guzzi and Ducati owners may be romantically attracted to your machine.
 
K

Kansas Bad Man

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Leaking fuel valves, or any thing else that is fuel related as far as leaks seem to have a life of there own, You can often stop them or slow them down but seldom with any longevity. At least that has been my experience, I try to replace with new if possible. Saves time and then theirs the problem of the wife asking , "what is the tooth past doing in the garage"o_O
 
C

cinquecento

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not sure about PTFE being fuel resistant, I was advised buy an 'old hand' to use soap as fuel would not act as a solvent and have used that on threads quite successfully.

I'll give the tooth spaste a go but have found you can order just the spigot although how these are measured isn't entirely clear but I'll go for the 1/4".
 
davidd

davidd

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Many say PTFE is not fuel resistant and it may be true. It should not be exposed to fuel in the tank, but I know that Pingel, the petcock makers, recommend it being used on the threads. Modern fuel system mechanics do not use it because "flecks" end up in the injectors or fuel filter. They prefer to use Permatex Aviation Form-A-Gasket Liquid Sealant Part No. 80019. The NAPA Part No. is 765-1210.

David
 
vibrac

vibrac

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David
I am always interested in the products you often suggest but I am amazed by the way american manufactures ignore the european market I get a sinking feeling when I follow "where to buy" and I get a map of the US "not found" is a strange way to reply to the entry "london uk" . But I suppose when you have the whole US market you can forget Europe
 
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