82 Leaking Petcock Query

[Rupert]

Hello everyone,

I have installed a replacement diapragm (new one from canadian place, can't remember name), but now the diaphragm seems to leak more fuel than ever.
I am confident that the screws are down tight enough and have even tried some liquid gasket around the sides of the diphragm which doesn't seem to have helped.
I had streched the internal spring earlier as I was trying out using some thicker diaphragm gasket material which was thicker.

Anyways, should I try a tiny bit of epoxy or something to seal around the diaphragm edges?

Cheers.

P.S. Bike runs fine, I'm just worried about the droplets of gas falling onto the frame and crankcase..

[Lucky]

You leave the bike on "on or "res" when it's off right? "prime" will let the fuel free flow.
you should never need/use sealer in the petcock.

couple of questions first:
--do you have a fuel filtere installed between the petcock & carbs? is it clean?
--is it an 82 petcock (single diaphram) or 83 (dual diaphram)?
--have you checked the carbs for dirt? if you have fuel comming out the overflow hose then you have to have 2 problems for that to happen, the petcock has to be leaking & one or both float needles have to be leaking.

if it's an 82 buy a rebuild kit from Keyster (on Ebay)  if it's an 83 i can make you a new diaphragm

--Lucky

& NEVER plug the drain hose, you'll end up with a crankcase full of fuel

[Rupert]

Thanks for the response lucky,

The petcock is an 82 and I leave it on 'on' for the test run about the block.
There is only fuel leaking around the exposed sides of the very thin diaphragm material on the petcock itself, I'll take the petcock assembly off and take it in to work tomorrow, check it's all tight etc.

Also There is only the stock filter installed in the tank, which I check some months ago and looked to be in perfect shape, no rust flakes either  ;D

Cheers

[louthepou]

Hi guys,

I wonder, Rupert, if the grey plastic part was repositioned exactly in the same way as when you dismantled the petcock. If I remember, this can matter.

I could take the time to take appart a spare one I have here if needed, I'm sure I would make more sense and be more helpful. But there are not many possible things that can go wrong with that petcock.

Let us know how things are, cheers!

Louis

[Lucky]

that would be my guess too, the plastic part of the diaphram has little 'posts' on it for poper positioning, & can be installed upsidedown.  that would cause a leak where it bolts together. 

also if the diaphram leaks there is a 'weep hole' in the plastic piece.  i know you kust replaced it but anything is possable.

You MUST install a fuel filter between the petcock & carb.  that so called filter on the petcock is worthless.

--Lucky

[Rupert]

I checked the petcock over and made sure all the surfaces are clean and put it back in again today.

umm, that weep hole, where does it goe? I've remounted it with that hole at the top, I think..

The locating holes were symmetrical I think so I removed them when I tried to make my own custom gasket, hehe whoops maybe..

I think I'll take the petcock off again tonight and apply a VERY fine layer of epoxy around exposed surface of the gasket/plastic part so as to seal the surface nicely. And I trust with the glue only being a thin layer it should be easy to remove with a knife etc should I need to dismantle the petcock again.

Cheers.

[Lucky]

weep hole should face down

[Rupert]

Thanks, I didn't take the time to see which way the petcock went together before I started to wreak havoc.

Whenever I reassembled the petcock I put the weep hole at the top, I'll put it back together today with the weep hole at the base and see how it goes, I don't really want to use any sort of glue on the outside of the gasket surfaces.

Cheers