petcock rebuild

[jdn40]

I need to rebuild the petcocks on my 78 . Mikes dosnt have anything for a 78 ( 4 screw back plate ) But I did find a kit on E-bay from a company called K&L .$38.95 + shipping per unit . Has anyone used this kit ? The replacements petcocks from Mikes for this bike are strange . They have one that is to be used on both sides . Seems to me that the off position on th left side would be towards the rear while the off for the right side would be towards the front . Pus replacement petcocks aint to cheap , any thoughts ?

 

[littlebill31]

He's got the whole '78 complete new petcock for $44.00.
And it's the non-vacuum type.

 

[jdn40]

I saw that littlebill but that is the one that is for both sides . wouldnt that mean left would be off to the rear while the right would be off to the front ? I guess it disnt really matter just kind of bothers me lol

 

[littlebill31]

If I'm correct, you can switch the port to either side. It just bolts on.

If you look close at the picture you can kinda see it. IMHO, I would make the tank a single petcock.

 

[jdn40]

never thought of a single , might look into it thanks . Might be something in the tech section ?

 

[littlebill31]

Or you can keep the duels. The little fuel nozzle can be switched to either side of the valve. Later models have a single, such as my '81, and work great. If you know someone who can weld good, just cover the right petcock hole. You would need to use a "T" bar connector for the carbs, but that is simple.

 

[Yamakazi]

I just received 2 of the Mike's XS non-vacuum type petcocks (part# 20-0019), and have taken a few photos if that will help. I also bought the blind plugs to cap-off the carb holder barbs. (I'll eventually switch to JBM rubber carb holders w/out barbs.)





Can't wait to swap these out for the leaky original petcocks I have now.

 

[5twins]

Where are your petcocks leaking from? Is it from the body or just dripping out the hose? If it's coming out the hose, you may be able to just flip the rubber disc over that's under the arm. You can also make your vacuum petcocks into manual ones if you'd like .....

http://650wiki.org/index.php/5.02.1_Vac_Petcock_Conversion

This can save a petcock that's leaking out the back around the vacuum plate or into the vacuum line.

 

[Yamakazi]

5twins...if you're asking me...the damage was totally newb inflicted (me). I removed the back of one of the petcocks and never could get it back on right. Pretty sure I screwed up the diaphragm. I'll figure it out one of these days (maybe with a rebuild kit), but I'm going with my new petcocks now to see how they do. I was faced with the same situation jdn40 was faced with...finding a reasonably priced rebuild kit for my 79 petcocks. They seem to be a fluke in the history of petcocks, and not heavily supported in the "rebuild" world.

I have saved the link you provided. Sounds like good stuff.

 

[jayel]

If I'm correct, you can switch the port to either side. It just bolts on.

If you look close at the picture you can kinda see it. IMHO, I would make the tank a single petcock.

yeah but the levers still go different directions (like on mine) don't bother me I got used to it

 

[littlebill31]

Crap, I never thought of that. Just having 2 petcocks would bother me. I'd forget somehow and often. I forget to turn the gas on with one.

 

[SpoogeMCMM]

with a single petcock you only need a T connector? do you have to change the size of gas line or anything? i need to put a single onto the sporty tank i bought and dont have much exp with dealing with such things lol

 

[bluebikerblan]

It seems to me that the return to a manual petcock versus maintaing the vacuum operated OEM ones is one of the real good idea contributions of MikesXS. As is the addition of another port which allows it to discharge left or right with a screw in plug on the outlet not used. ie one design model adapted for left or right to be used for either single or dual outlet tanks.

K & L makes a good rubber parts & gasket replacement set which can be made to work pretty well but; one is left with wondering...."why is it now that I want vacuum operation" in the first place as opposed to the certainty of a manual "OFF"-"ON"-"RES" ?

Converting to manual petcocks is right up there with eliminating the self-cancelling turn signal units.....my opinion. It would be interesting to know of others as I'm still looking for the redeeming feature of a internal spring diaphragm off and vacuum on? Beats me.

There are a lot of ways to skin the cat of either converting the old Vacuum petcocks to manual or using the Mikes units which work quite well in my opinion. Z-1 Enterprises and others offer other manual alternatives as well. Blue

 

[bluebikerblan]

I need to rebuild the petcocks on my 78 . Mikes dosnt have anything for a 78 ( 4 screw back plate ) But I did find a kit on E-bay from a company called K&L .$38.95 + shipping per unit . Has anyone used this kit ? The replacements petcocks from Mikes for this bike are strange . They have one that is to be used on both sides . Seems to me that the off position on th left side would be towards the rear while the off for the right side would be towards the front . Pus replacement petcocks aint to cheap , any thoughts ?

You do know that you can convert your existing vacuum petcocks to manual ones? You can also get a pretty good selection of repair gaskets & kits here:

http://650wiki.org/index.php/5.02.1_Vac_Petcock_Conversion

http://stores.ebay.com/Sirius-Conso...aha+xs650&submit=Search&_fsub=7&_sid=24743148

Blue

 

[retiredgentleman]

bluebikerblan;

Blue, I totally agree with you...............manual petcocks are the way to go. When I first got my 78SE, 4 years ago, the first things that had to go were the buckhorn handlebars and the vacuum petcocks. I don't want a petcock that does not have an "OFF" position.

The manual petcocks from Mikesxs work great, and just as jayel mentioned, they turn off in opposite directions, which I find seems normal now.

Oh yes, the turn signal cancelling unit had to be removed as well..........safety item!

 

[weekendrider]

blue, Pete would argue the safety of having it shut off if you go down. Something of a personal experience for him, if I remember correctly.

moovova, you might check the screen filter in the petcock. Mine were open ended. A little soldering will fix them.
The 90 degree outlets probably won't line up right. Seems like mine stuck out instead of in with the original washers. A thicker fiber washer fixed it.
And the cute little stem filters, save yourself the time off trying to shake them out later.
Ethonol isn't kind to them.

 

[bluebikerblan]

blue, Pete would argue the safety of having it shut off if you go down.

Hadn't thought of that! At last a redeeming feature, otherwise they're a PITA! Blue

 

[littlebill31]

I like the one petcock with non-vacuum. Right next to the choke, only one to worry about, off/on/res. I can understand the safety factor, but if the bitch ain't runnin' right due to a crappy petcock...

My friends had a vacuum petcock. Is was really fun having it stumble at speed, then die from lack of fuel. Even more fun in traffic.

 

[Yamakazi]

moovova, you might check the screen filter in the petcock. Mine were open ended. A little soldering will fix them.
The 90 degree outlets probably won't line up right. Seems like mine stuck out instead of in with the original washers. A thicker fiber washer fixed it.
And the cute little stem filters, save yourself the time off trying to shake them out later.
Ethonol isn't kind to them.

Thank you for the info. I installed the petcocks last night...basics seem to work well, but haven't taken it out on the road yet. I noticed the metal filter inside the petcock seemed a little long when I swapped out the inlet valves but went with it like it was for right now. It looks like it was made to lodge between the inlet valve and the blank inlet bolt on the other side.

That bothers me about the ethanol vs the plastic filters. I thought they looked a little "weak" to begin with. So, non-ethanol gas would be better for those little devils I guess. I'm wondering if you could solder on a small closed-ended metal filter (like the internal petcock one) to the pipes extending up into the gas tank.

I found myself running back downstairs to the garage last night because I had not turned the petcocks "off" when I finished. I was so in the habit of just walking off with the old vacumm type without turning it off.

 

[KenN]

Another problem with vacuum petcocks, my son has one on his Honda SC650, if you aren't lightning fast switching the valve when the tank runs dry, you run all 4 carbs dry. At that point there is not enough crank in the battery to tun the engine over for 5 minutes to fill the bowls again, and you have to push for 100 yards before it starts.