Problem with fuel taps

Information relating to the Matchless G5 or AJS Model 8 350cc Lightweight
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bigal2rf
Posts: 10
Joined: Mon Dec 28, 2015 3:36 pm
Location: N Ireland

Problem with fuel taps

Post by bigal2rf »

I recently had my fuel tank off the bike for a respray and had to remove both fuel taps.
I noticed that the threads had been sealed with PTFE tape.
Ive replaced the tanks and put tape on the threads but both taps are leaking when turned on.
Should the taps have a sealing washer fitted...cork washer or similar? Or am I missing something that should stop the leakage?
The tank had been taken off prior to my buying the bike and the taps may have been wrongly refitted.
Any advice welcome.

Alan
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Stuoyb
Posts: 1229
Joined: Tue Jul 27, 2004 1:00 am
Location: BEDFORDSHIRE UK

Re: Problem with fuel taps

Post by Stuoyb »

Minimum they need is a fibre washer.
Best solution is a dowty washer.
Using PTFE tape it is too easy to overtighten and strip threads or shear the tap.
Depending upon size (1/8 or 1/4 bsp) it is best to clean the the thread with the appropriate tap.
bitza
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Posts: 452
Joined: Tue May 27, 2003 1:00 am
Location: SHROPSHIRE UK

Re: Problem with fuel taps

Post by bitza »

I go along with previous comment, had my tank repaired, repainted, clean out tank threads with correct
Tap, refit fuel taps using fibre or dowry washers not ptfe
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Expat
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Posts: 1033
Joined: Thu Nov 12, 2015 2:22 pm
Location: Tennessee, USA

Re: Problem with fuel taps

Post by Expat »

If the taps are leaking only when turned on, surely the problem isn't the seal between the tap and tank, or am I missing summat?

Mine has the brass petcock type and they are inclined to weep if the lever part is too loose in the tap body. When tight though, it is a bugger to turn on!
Keep shiny side up.

These are my principles, if you don’t like them, I have others. (Groucho Marx)
56G80S
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Posts: 3353
Joined: Wed Oct 12, 2005 10:45 pm
Location: N YORKS UK

Re: Problem with fuel taps

Post by 56G80S »

"If the taps are leaking only when turned on, surely the problem isn't the seal between the tap and tank"

I was thinking the same thing. I've only used fibre washers for tank to tap fitting and that's not been a problem. I wouldn't be too keen on the PTFE either.

I'm using Ewarts push/pull barrel type taps and the round corks. Although I read lots of reports of problems with the corks, it's not been so for me but the taps are turned of and on pretty often.

I'd look elsewhere. Difficult to track petrol!

Johnny B
bigal2rf
Posts: 10
Joined: Mon Dec 28, 2015 3:36 pm
Location: N Ireland

Re: Problem with fuel taps

Post by bigal2rf »

Thanks folks...correct washers ordered up and I'm fitting 2 new fuel taps as well for peace of mind.
Amazing the shortcuts and bodges you find when doing these jobs.Its great to be able to access speedy advice from forum members!

Alan
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