How do I rebuild Mr. Petcock?

[Coil Coyle]

 I found this with a search, It was from when you first looked for a part in Swap

"place the new diaphragms where the center screw holes overlap,using the pilots to guide them place small amount of silocone gel on the seam (not silicone sealor) but gel, that product will not harden. never use silicone sealor of any kind where it will come into contact with petroleum product, gas, oil, or grease it will not seal there are some advertized that they claim will work but i wont try it on my bike so i would not use it on any one elses" !! ???

Wait, maybe he meant allign the holes with the diaphrams rotated 45 degree, 2 holes up 4 along the center and 2 down

 ::) Do they fit that way and center the valve over each port?

My parts our coming I sure hope this works.
coil

[ProfessorRex]

I don't mean to pull a Humber, but really guys, obviously this isn't going to work, from the pictures the diaphrams look too small.  

The real question is WHY BOTHER?  
With two valves, or maybe just one on the fuel line, not the return line you can aleviate the leaky petcock problem.  Seems to me that is a much simpler and less exspensive fix than trying to use two '82 kits.

-Rex

(By pull a Humber, I mean giving a strait opinion without caring about anyones feelings, see his post about Extents Sport Faring Project)

[dchakrab]

Since I'm still not entirely sure what the diaphragms do here, I'm just following what people advised on the boards...they did look too small for the depressions they're fitting into, but I'm not sure what that means in terms of them working...does that mean the petcock won't work, meaning I'm going to have fuel flowing all the time into the carbs (and flooding)?

How can I keep the petcock from leaking into the outside world?

I used a liquid gasket thingy to seal the petcock assembly to the underside of the tank just now, for added protection from leaks, and I'm thinking about opening the petcock again to apply a layer around the outside rim of everything, to keep the gas in the petcock. Then, an on-off valve on the tubes, and I'm done?

Final question...tubes. What goes where? I'm clueless, but I swear there's more tubes in that area now then there are places to put them on the petcock, and this medusa of a bike seems to grow two new ones every time I look at it. I'll run down, grab a picture, and post back...someone please tell me what to connect to what so I can at least test this.

  Thanks,

   Dave.

[dchakrab]

Here's the left side of the bike, with the lower fairing removed:



There seem to be two extra, longer tubes coming from further back towards the front of the bike, which don't seem to go anywhere...what are they, and where should they go?

One of the other tubes, probably to the petcock, has what looks like a red plug inside it, blocking it off?

There's a red plug on the petcock, blocking off one of the nozzles...is this the vaccuum intake? If so, should I unplug and connect it?

There's a tube that comes through the middle of the bike, which is held by a black U-shaped holder or fastener...which one is this?

And finally...the tube that I assume is the main fuel tube is really short, and the inline valve with the barbs is large. I can make them fit by using a lot of extra line, but this will probably result in a loop...will that work, or will the fuel flow not work against gravity? Where would I stick an inline fuel filter, once I find one?

Thanks for all help and advice. Maybe if someone could open the picture in paint, and just color the tubes different colors and tell me which one goes where on the petcock?

  -Dave.

[jasonm.]

I have the answer to fixing any petcock diaphragm assy. FIRST, after taking it apart. Look at the diaphragm. Is it cracked or holed? IF NOT...then the leak is simply the o-ring on the plunger part. YES, the plunger is what allows the fuel to flow. Just replace the o-ring with a viton or other gas proof type and your in business. Even in the fuzzy pics, Dave's o-rings look worn out.
 If the diaphragm is shot...then it is time to prey for a part(s) from another model that might work.   p.s. that red plugged hose in the picture is THE VACUUM hose for general fuel flow. That's where you can use an '82 part. What that red thing is there for I have no clue. The best thing may be to get a manual off ebay.

[dchakrab]

At least one of the diaphragms on mine was worn through completely...if I lifted it slightly I could see the holes all the way through it.

I'm entirely unsure if the current patch job I did on it with the Sirius parts is going to work or not...it seems highly likely that I'm going to end up just trying to seal the petcock from external leaks, and let it leak into the tubes, which I can control with an inline valve.

Superfly may also have a spare petcock for me, which would be ideal!

This means a total waste of $55 or so on the Sirius parts, but I'll be happy if I can actually hear the engine on this thing today.

  -Dave.

[dchakrab]

Crappity crap.

Petcockenstein refuses to walk, lurch, grunt, or so much as twitch...no matter what I do, engine won't turn over, probably because that giant loop of tubing is prevent gas from riding uphill into the carbs.

More importantly, the experiment was a complete failure...the diaphragms do nothing (too small, almost definitely) and the petcock leaks *WAY* too much gas out onto the concrete for this to be a working solution.

Next step: I'm going to open the petcock and try to seal it completely with the liquid gasket stuff, and see if the sealant helps or stops the external leaking at all. Oh, and I'm going to cut a smaller length of tubing, if I can find some scissors, so there's actually some gas going into the carbs. The last thing I need is to kill my battery trying this...cheapest charger I saw was $50.

  -Dave.

[dchakrab]

Round two: no luck. I have sealant all over my table, my keyboard, and my fingers. The thing seemed like it was mummified...I thought I had it licked.

So i waited for all the crap to dry, and tested it with water from the bathroom tap. Holding the petcock at an angle, with the water running in the main fuel intake stem, water runs out from the nozzle meant for the fuel return from the carbs. What? So I stop that with my finger, switch to prime, reserve, and on...no difference. I can't make the water come out of the main fuel outlet, the one under the drain screw. I figure I must have clogged something inside. No biggie...I can put the intake tube on the nozzle that's squirting out gas, and figure out what to do with the fuel return line later.

I blew into both tubes, though, and neither seemed blocked or plugged. In a couple of minutes, though, I noticed a tiny leak spring up on the sealant I used around the edges of the petcock assembly (the rectangular pandora's box with the six screws).

That seems to be the only leak, apart from the obvious problem of nothing coming out of what's normally the fuel output hose.

Is it worth cracking this thing open and re-mummifying it? Or is this doomed? I'm assuming that if it's sprung a leak, it's never going to hold, no matter what I try with it, so I'm about ready to give up...Superfly's got a petcock he's willing to sell me, so I'll just have to be patient and wait for a while.

Of course, if anyone's got any ideas, or thinks I should give this another shot, I'm definitely willing.

  -Dave.

[ProfessorRex]

Well... looks like we really need that 82 to 83 adapter plate.  Sorry man, I can't think of how to help you fix it.  I can think of how you could make something that would work in the meantime (maybe).

First:
-Do you have a way to cut metal? = dremel, grinder, etc
-Do you have a drill?

I'll try to explain the way I think you could make it work, but you may need to call me if this is unclear.

Ok,
-get a piece of thin flat stock about 1/8" the type of metal doesn't matter
-Cut it into the shape of the base of the petcock where it mates with the tank
-Drill the holes to mount it
-Drill a hole and insert a barb for the main fuel feed.  Seal it well!
-Drill another hole for the return, insert a barb, but this time (I don't have an 83 so I'm not sure if the level matters. Lucky?) attach some sort of metal tube to raise the level at which fuel is returned
-Put sealant on the base and screw it into the tank

GOOD LUCK, PM me if you need my number for a better explanation

-Rex

[dchakrab]

I think I vaguely understand what you're thinking, but I have no drill, and no dremmel. The cheapest Dremmel at Ace is $20, plus another $20 or so for an assortment of Dremmel blades/attachments. I'm hesitant to spend the money when I've spent so much on bike + tools already, and have yet to so much as hear the engine run :(

I'd be willing to give it a shot once I have a little more money, or once I have the title and related expenses taken care of, and know exactly what I have left to spend. By then, I'll probably have the petcock from Superfly, so hopefully it won't be necessary.

Thanks though,

  Dave.

[Coil Coyle]

OK, I give.
I reassembled with Viton Orings and went for a ride, Jason :-*

Now I will A: keep bugging Sirius to develope a 83 kit
              B: keep these 2 82 kits for my next swap oportunity.

Dave, I owe you one for trying this guys fix first. Gravity will not stop your gas but a big bubble of air will take a long time to pump through your fuel pump at starter cranking speeds.

If I find a 83 tank valve out here, its yours.
coil

[louthepou]

Indeed, thanks Dave for giving that a try, I'm pretty sure lots of us gain from this.

If you ever go for the 82 petcock, I know a few of us must have spares lying around...

Louis