Leaky Petcock

[ddragon63]

Hey guys just wanted to pass one by ya. My left hand petcock likes to give me a few dribbles of gas when I switch from one selection to the next. I know I could probably fix it by taking the front apart and re-springing the collar washer a bit. I have not a clue the last time these things were gone thru...

I'm thinking about buying the rebuild kits and just going thru the both of them

I know only one leaks but I look @ it like Brake calipers... if you gotta do one you oughta just do both while your at it, and you best do it right the first time.

Anything I need to watch out for when I pull these things apart? Remember this is a standard tank on a special so they both have diaphragms

Thanks

[bikerphil]

Yep, those vacuum operated petcocks are finicky to rebuild. Supposedly if you polish the o ring seat and the selector knob, you will have better luck. If they are leaking externally, you're gonna need rebuild kit anyway. Maybe someone will chime in who knows the best rebuild kit to get, maybe the K&L?

[ddragon63]

Yep, those vacuum operated petcocks are finicky to rebuild. Supposedly if you polish the o ring seat and the selector knob, you will have better luck. If they are leaking externally, you're gonna need rebuild kit anyway. Maybe someone will chime in who knows the best rebuild kit to get, maybe the K&L?

Thats what goerge fix sells... not bad priced like $28 each. I've looked @ the exploded view in my service manual and it looks pretty straight forward. But I also though that with the first Vacuum fuel pump I tore into on a big 2stroke outboard. it can apart without a problem but trying to figure out where the jack in the boxes fit back in was fun

We use to resurface the sealing face of our petcocks in our dirt bikes when I was a kid to get better flow out of them. Basically to remove the pitting from fuel, dirt, factory crappy castings, etc... I'm assuming this is what your referring too??

[XS1100_OEM4ME]

Petcocks

$60.00+ with S/H to rebuild both is kinda high to me, but my cash is tight now. If only on leaks and only when you turn it, could try this 1st, dont know the year of your standard so check for fit 1st
http://www.ebay.com/itm/yamaha-xs110...sories&vxp=mtr

[ddragon63]

$60.00+ with S/H to rebuild both is kinda high to me, but my cash is tight now. If only on leaks and only when you turn it, could try this 1st, dont know the year of your standard so check for fit 1st
http://www.ebay.com/itm/yamaha-xs110...sories&vxp=mtr

yes i'm assuming this is where its leaking from sure I can find the o-ring in the hardware store.. it dribbles onto the drain plate... seems to only happen when turned to prime.

Only reason I was thinking about kitting both sides was to get 2 fresh diaphrams in it. Ya 60 bucks is a few more than I'd like to spend myself too... always seem to run out of money before I run out of projects.

[XS1100_OEM4ME]

K&l

I used the K&L kit on my Special, the petcock parts worked OK, but the diaphram wouldn't seal, so I ended up just cleaning the old diaphram, put it back in and it worked fine (only one on the special because of the octy) don't knoe if just my luck or what

[ddragon63]

I used the K&L kit on my Special, the petcock parts worked OK, but the diaphram wouldn't seal, so I ended up just cleaning the old diaphram, put it back in and it worked fine (only one on the special because of the octy) don't knoe if just my luck or what

I was reading up on older post and that seems to be a recurring issue with special octy's and new diaphrams.... I couldn't find much useful info on standard petcocks so I posted my own thread. every thing seems to work good in both of them... I just dont wanna find out my left leg is getting warmer because its on fire!

[old_skool]

My left hand petcock likes to give me a few dribbles

I'm surprised nobody found a joke in here somewhere....

[GLoweVA]

On my standard, the rubber insert, (the one with the 4 holes) had gotten a little "chewed up" from all the years of turning. So, it wasn't seating very well and I had a little gas 'leaking by'.
I ended up flipping it around so the 'newer' surface was against the petcock housing and the 'chewed' up side was out towards the lever.
I also lubed it up a little so it would turn a little smoother and not 'drag' so much.
I also 'stretched' my wavy washer just a little bit to give it a little extra push to make it seat better.
the diaphram was in decent shape and the o-rings were okay, I just made sure they had a little lube on them.

Caution: those diaphrams (2 of them per side) can get really stuck to the housing. Be very careful when separating the pieces so you won't tear it. Then you'll have to definitely get a replacement.

[ddragon63]

On my standard, the rubber insert, (the one with the 4 holes) had gotten a little "chewed up" from all the years of turning. So, it wasn't seating very well and I had a little gas 'leaking by'.
I ended up flipping it around so the 'newer' surface was against the petcock housing and the 'chewed' up side was out towards the lever.
I also lubed it up a little so it would turn a little smoother and not 'drag' so much.
I also 'stretched' my wavy washer just a little bit to give it a little extra push to make it seat better.
the diaphram was in decent shape and the o-rings were okay, I just made sure they had a little lube on them.

Caution: those diaphrams (2 of them per side) can get really stuck to the housing. Be very careful when separating the pieces so you won't tear it. Then you'll have to definitely get a replacement.

Thanks I might give that a shot. They seem to pump fine. I'm just no a fan of gas leaking... well anywhere

I'll take the face of it apart and flip the rubber seal... the best lube in the world for o-rings is White Lithium Grease. I use it on diesels and gas motors. you'd be amazed at the life it will give fuel o-rings. A farmers tool box is not complete without a tube of it

[ddragon63]

I'm surprised nobody found a joke in here somewhere....

yes.... when i switch it around too much it dribbles....

[old_skool]

are there any lubes.....{now we're getting back to the joke again}...are there any lubes that will actually stay in contact with the gaskets or diaphrams that won't be washed away by the gas right away??

[ddragon63]

are there any lubes.....{now we're getting back to the joke again}...are there any lubes that will actually stay in contact with the gaskets or diaphrams that won't be washed away by the gas right away??

Lmao! Yes we are. I can't speak from gasoline experience. But i know that we've used white lithium grease on diesel onjectors o-rings just for that purpose. It won't was and it keeps the seal soft.

[motoman]

GLowe has it right. Being a Standard, no real reason to rotate petcock anyways, if you keep gas in the tank. Aside from that, just take petcocks off the tank, take apart anf clean. Very slightly stretch the spring on both, smear a thin film of dialectic grease on gasket parts and diaphram contavt surfaces, put back together and go ride. Don't need no stinkin kit, specially K&l,,,they dont seem to have proper fit on the STandard petcocks, which doesn't surprise me any considering the brand. If nothing is torn, the above I stated WILL work, every time on the Standard petcocks, least from my experience.

[GLoweVA]

I did modify my petcocks a little. I ground off the little nub at the top so I can rotate to the 12 o'clock position and have and 'off'.
I like that, so that I KNOW that the thing will not flow at all.
This is especially useful when you go to pull the tank off and you take the hoses off the petcocks and THEN you find out that one of them leaks because the diaphram isn't seating right.