Well, I checked again this morning, no drip, no weep, nothing! Dry as a bone! Lighting is bad in my shop, but I could see clearly with my cigarette lighter.
Just joking, but I could have if I wanted to!
So here it is.....the mother of all push/pull repairs!
Head down to your local cycle shop and get a hunk of fuel line, polyurethane, 3/8 OD X 1/4 ID. get a length long enough for easy handling while cutting, and practice cuts. Get some nice sharp single edge razor blades.
Disassemble the petcock, clean the barrel.
Being very careful to make a square, even cut, trim the end of the hose. Trim it a number of times for practice if need be. Since most fuel lines are stored coiled, there will be a bit of a curve, so be sure to cut perpendicular at the cut point, and ignore the slight bow in the material to each side of the cut.
Once you have a nice flat end, time for the important cut, the one for length. Cut it flat again, one RCH longer than the distance between the brass pin and knob. Do not use the cork as a measurement.
Now, I know your are reading or looking at this and saying, " Hey newbie, that brass pin is much smaller in diameter than the 1/4 ID of the tube!", and you are quite correct!
With this repair, we are looking for a tight seal to the barrel, achieved by the slightly larger diameter of the fuel line. The seal between the brass pin and knob is created by compression of the diameter of the line, as well as compression lengthwise when the pin is pressed back in. Any slight curvature in the line will be straightened when the petcock is reassembled.
When you have what you think is the right one, reassemble and tap the pin back into the knob and test fit. When reassembled, it should go in rather tight. Happy with that? Pull it back out and carefully stake the end of the pin in the knob with a small sharp chisel.
Dab of oil, and reinstall.
When singing "Kung Fu Fighting" is outlawed, only outlaws will sing "Kung Fu Fighting"
Let us not be too quick to dismiss this neoprene hose idea. OB1, let us know how this works out over time, but I'm betting that the neoprene will hold up better than cork.
Tip for cutting hose straight: First wrap a piece of tape around the hose. When you are satisfied that the tape is on there squarely, just cut at the edge of the tape.
My other 2 cents: I had new spindles made for my Ewarts' taps, a bit longer and with a groove near the end for a hairpin or an E-clip. You could also cut a thread on the end for a nut, but in any case, this makes it easy to disassemble the plungers and replace the cork or hose or whatever.
So far, so good. The valve action is very, very tight. I am thinking of re-doing the hose with a few shallow rings cut around the hose to allow for compression of the hose. That should make the action easier, and not detract from the seal.
When singing "Kung Fu Fighting" is outlawed, only outlaws will sing "Kung Fu Fighting"
Re: Push/Pull petcock repair that works!#57204 10/03/071:19 pm10/03/071:19 pm
I just had the problem of mine being too tight, such that I couldn't open or close it by hand. It had already been "upgraded" to something rubber and hose like, but whatever it was is not impervious to gasoline. the rubber would swell where it contacted the gas, and fill out into the hole it was supposed to just block. when I pulled it out, it would rip a little chunk out of the rubber...
so I found a piece of oil line, but it was too thick. I put it on a bolt and ran it in the drill press with a piece of sandpaper to "shave" it down. once it fit snugly, tight but moveable, I put it on.
now my brass plunger (pin) has threads on it, and the knob threads onto it. I can see that there was actually a straight screwdriver slot on the end, but one side has broken off. I'm sure that is was to adjust the extent of the compression after it was all installed, but is useless to me now.
anyway, what I found was that this setup still wept a bit of fuel around the knob when installed at a decent compression to still pull it by hand.
what I did then was to take out the stop screw that "locks" the knob in the pulled open position. without that stop screw I can fully release the compression, pull the plunger (gently, since there's nothing stopping it from coming out completely anymore) then tighten it to compressed status again, this time in the open position. and vice versa.
what I think I will do, unless I learn of a better mousetrap, will be to mill the groove in the knob into a full circumference of the barrel on both ends of the push pull direction. that way it will have a full revolution for compression/decompression movement, and still have a stop when you pull it out.
does any of that translate from my head?? ;-)
================= /1957 BSA A10 Spitfire Scrambler (in a friend's shed) /1960 BSA Super Rocket Basket Case (in the attic!) /1987 BMW K100LT nekkid
Re: Push/Pull petcock repair that works!#57208 10/09/079:13 pm10/09/079:13 pm
does anybody make better shutoffs??????If they are out there i`ll find them.enough of these pet cocks. i haven`t had any trouble with the rebuild kits from walridge. Has everybody had bad luck but me?????? :rolleyes:
Bob S Street Rods, Kustom Kars,A BSA,Cushmans,H.Shadow ACE, Now a 2004 triumph america . "More than enough!!!!
Re: Push/Pull petcock repair that works!#57209 10/09/079:50 pm10/09/079:50 pm
Ob1 and all, You may not need to replace the cork just because the petcocks leak. If a bike sets idle for a time with an empty gas tank the cork will dry out. The fix is to remove the plunger assembly. don't take it appart any further. Bring a small pan of water to a boil and shut off the flame. Put the plunger in the pan for about 5 min. Take it out and pat dry. give the cork a thin smear of Hylomar or vasoleen or silicone grease and reassemble the petcock. as long as the bore isn't scratched or pitted, this should fix the leaking. I have also found that new replacement corks are not as good of quality as an old cork. HTH Cheers Dennis B
For over a year now I have had no leaks at all from the ewarts corks. I just rub a little softened bar soap into them and they never leak again. And they slide in and out like they are on ball bearings. I never boiled them or anything like that... just a little bar soap. Grease, silicone grease, or the like will wash away with the gasoline. Try mixing a little soft bar soap with gas. It just turns into what seems like thick, sticky, grease. It will not dissolve in gas.
"he who laughs fast, laughs first"~Gunk
Re: Push/Pull petcock repair that works!#57213 10/10/077:56 pm10/10/077:56 pm
I'm with Dennis B,My father and grandfather who rode bikes from the 1940s onwards used to remove the leaking corks and place them in boiling water for 15 minutes and allow to dry naturally then refit,no more leaks(well at least for some time)it worked for them.Cheers,Paul.
I'm gonna have to try some new ways to seal up these old ewarts, I bought a few sets of O-ring repair kits and they're both weeping fuel a few months later....not to mention they were very hard to open.
I haven't had success with the o-rings. They tear along the edge of their groove. I boil the corks, that works for a while until they get well dried out from no fuel on them. I'll have to try the soap.
I've had great success with making new corks from the synthetic wine bottle corks. And the benefit is the "special lubricant" that comes from the bottle with the cork.
1967 BSA Wasp 1967 BSA Hornet (West Coast Model) 1967 BSA Hornet (East Coast Model) 1968 BSA Firebird Scrambler 1968 BSA Spitfire Mark IV
I too started to make synthetic corks from all those leftovers that GaryE refers to. We had a discussion under"ewarts cork leak" many months ago - mine are over a year old and don't leak externally or internally. They are also easy to open and close. Never could solve this problem with o-rings or fuel line - but it seems like OB1 is onto something. Leon
I tried the O rings poor results. Then I used the wine cork most likely synthetic, carved basic shape then rounded it on sanding disc, drilled hole boiled until oversized, sliced the side then squeezed it into place now not a drop of fuel. 20 min max
This topic ranks up there with "A series plain bushings" and "wet sumping". What's nice is there are some good answers out there. I tried "O" rings and they did not work, but the " slit corks in boiling water" did. Not perfect, but a pretty darn good solution with little time and effort invested. I like the soap for a lubricant...my Dad always had a bar in the shop fora variety of lube purposes...so I'll try that next time I have to "boil corks" which comes around every year or so.
Ob1 and all, You may not need to replace the cork just because the petcocks leak. If a bike sets idle for a time with an empty gas tank the cork will dry out. The fix is to remove the plunger assembly. don't take it appart any further. Bring a small pan of water to a boil and shut off the flame. Put the plunger in the pan for about 5 min. Take it out and pat dry. give the cork a thin smear of Hylomar or vasoleen or silicone grease and reassemble the petcock. as long as the bore isn't scratched or pitted, this should fix the leaking. HTH Cheers Dennis B
At the start of each riding season, I've used the boiling water technique to recondition, hydrate and soften the corks. This extra effort provides a good seal for several months, but have recently found that I've got to repeat it during the year. Why? I'm sure that the ethanol in fuel is slowly absorbing the water from the re-hydrated cork body causing shrinkage.
It would seem that the (approximately) 10% alcohol in modern fuel is a factor in this problem and may be the reason this needs doing a little more often but there is one more thing you can do (provided your cork is in good shape) put the plunger assembly in a vice (lengthwise) , and give it a VERY gentle squeeze only looking for a tiny bit of movement here this will make the cork just a little fatter HTH Cheers Dennis B
I like this wine bottle cork idea! Gonna give it a shot....off to the liquor store first.
No no ! An old olive oil cork would be better. Similar. hydrocarbon (fuel) to hydrocarbon (cork) interaction.
Seriously though, pre-immersion of the dry cork in the fuel of choice should be the better solution to the problem. (That is, if you've got the time to truly care for a vintage bike. Sorry, I couldn't help it).
Hi guys, I have a friend who makes a replacement plunger for me that I sell on eBay. It isn't the cheapest solution, but your bike catching on fire (or your pants) isnt either. There are many different ways I have seen this done, but only one that I liked. This plunger is made to look just like the original when installed, it even has the lettering. You dont have to cut, sand, soap, drill, or rivet anything. Drain the gas, remove the tiny guide screw, pull out the old plunger, insert the new plunger (pre lubed) install the original guide screw, done. There was a nice write up on them recently in the Ohio valley BSA owners newsletter.
I do use 2 fuel proof o-rings that work on any pump gas. They DO NOT cut or tear, as they are the correct size & in the correct size groove. The lubricant took me a couple of years to figure out & is a closely guarded trade secret. Most lubricants will wash off & do bad things inside your carb, this lube wont wash of & is nice & slippery.
If anyone wants one (or more) PM me & mention the BBF & I will gladly discount them 20 percent for a limited time & will offer a 100% refund, including shipping to anyone who isnt thrilled for any reason at all, no questions asked. I have not had a single return yet & have sold over 300 of these locally & on eBay.
Magneto & Dynamo restorations & supplies
My Bikes 1950 Norton Model 7: 1952 Norton ES2 1957 Norton Model 77 1960 Norton Nomad 600cc 1961 Norton ES2 (slimline) 1964 Norton Atlas Scrambler 1972 Bultaco Alpina