Manual Petcocks

[randy]

Petcock conversion to manual???

I've been considering this mod, anyone ever done it?

http://www.xs750e.com/page25.htm

[Rev.Rick]

I just like the simplicity of things and the fewer splices in the fuel lines the less chance of leaks. By the way Mstaab are you or were you a member of the Yamaha Triples forum? It seems like I remember your signature and quote from that site.

[oseaghdha]

I've been considering this mod, anyone ever done it?

http://www.xs750e.com/page25.htm

Randy,
Can't find the post but there was one solution where you solder up the curved slot in the lever, remove the diaphragm and block off the back side of the housing with a gasket to turn the STD petcock into manually operated.

I did this on mine. Just make sure it's clean and use solid core solder with brush applied flux. Works great. I used silver based rather than Pb.

I also suspect you can just swap Special levers into a STD housing and get the same effect (without the solder), but I have not verified this theory yet.

[randy]

Dan,

Excuse my ignorance, but, wouldn't soldering-up the slot cut off the fuel completely?

[fredintoon]

Just wondering, the petcocks have an "off" position so why, if everything is working correctly, would you want to remove the "octy"? It would simplify things I guess but if it aint broke...

Hi Mstaab,
have you checked how many fuel and vacuum lines are used on the octopus installation? Compare it to the two you need without it. I would say that the more accurate thing to say about a functioning octopus set-up is " it ain't broke - - - yet."

[bikerphil]

Here's more on soldering the petcocks in this thread, post # 6. After soldering, I tapped the solder piece out and JB welded it in back in place. Without doing that, it would leak. I've done this to a couple bikes and it works great. YMMV

http://www.xs11.com/forum/showthread...solder+petcock

[oseaghdha]

Dan,

Excuse my ignorance, but, wouldn't soldering-up the slot cut off the fuel completely?

Randy,
The STD petcock lever has a straight slot and a curved slot.
The plan is to only fill the curved slot. The straight slot will be the feed because the diaphragm and it's associated 'piston' are removed. This allows the feed to go thru whenever the the straight slot is lined up with either the run or reserve. The off position is the old PRI position, which will be an N/C now.

I mean to test the special lever in the STD housing tomorrow, may be the simplest solution.

[DGXSER]

MStaab,

In my case, and often others, the OCTY valve sticks in the closed position, o the vacuum can not pull it open to let fuel to the carbs. So it went By-By.

[WMarshy]

Randy,
The STD petcock lever has a straight slot and a curved slot.
The plan is to only fill the curved slot. The straight slot will be the feed because the diaphragm and it's associated 'piston' are removed. This allows the feed to go thru whenever the the straight slot is lined up with either the run or reserve. The off position is the old PRI position, which will be an N/C now.

I mean to test the special lever in the STD housing tomorrow, may be the simplest solution.

oseaghdha, did you ever try putting a special lever in the standard petcock housing? Has anyone else tried this yet? Seems like if it fit and worked the same as filling the "J" slot in the standard lever everyone would be jumping all over that mod... Someone please advise, Im considering replacing mine with on/off ones or filling the "J" slot in my std's. I have a set of levers from a 79 special but Im about 2 hours from my bike and parts... Thanks

[WMarshy]

I think I read somewhere about swapping the left and right levers (cannot quite remember specifics, help me out if you know what Im talkin about) Swapping the levers reverses the functions as compared to the indicator plate but, it also makes one of the position an off position. Anyone remember reading this or have experience doin this? Thanks!

[cywelchjr]

Randy,
The STD petcock lever has a straight slot and a curved slot.
The plan is to only fill the curved slot. The straight slot will be the feed because the diaphragm and it's associated 'piston' are removed. This allows the feed to go thru whenever the the straight slot is lined up with either the run or reserve. The off position is the old PRI position, which will be an N/C now.

I mean to test the special lever in the STD housing tomorrow, may be the simplest solution.

Once the diaphram is gone, how do you keep it from leaking out the back? Do you seal up the vacuum port as well? I have an extra set of petcocks for mine, so I can experiment with them, as the ones on the bike are working at the moment.

[crazy steve]

Randy,
The STD petcock lever has a straight slot and a curved slot.
The plan is to only fill the curved slot. The straight slot will be the feed because the diaphragm and it's associated 'piston' are removed. This allows the feed to go thru whenever the the straight slot is lined up with either the run or reserve. The off position is the old PRI position, which will be an N/C now.

As an alternative rather than alter the lever, if you plug the bottom hole on the petcock body you'll have the same result. As to the vacuum diaphram assembly, fab a blank cover to take it's place.

Swapping the handles side-to-side won't work; you'll lose the reserve function.

'78E original owner

[bikerphil]

If you guys are modding the Standard petcocks, leave the diaphragm in, it'll act as a gasket, but remove the O-ring. Put the spring on the opposite side, to hold the diaphragm in the open position. Plug the vacuum port. I filled the channel in the petcock lever with solder, flattened it with a file, then fine grit sandpaper. Then I tapped the formed solder piece out and glued it back in place with JB Weld. I tried it first without the JB Weld, and it seeped. Mine is working fine (I only run one on the left) for the last year, no drips when in the prime (off) position. My right side has a block off plate.

[cywelchjr]

If you guys are modding the Standard petcocks, leave the diaphragm in, it'll act as a gasket, but remove the O-ring. Put the spring on the opposite side, to hold the diaphragm in the open position. Plug the vacuum port. I filled the channel in the petcock lever with solder, flattened it with a file, then fine grit sandpaper. Then I tapped the formed solder piece out and glued it back in place with JB Weld. I tried it first without the JB Weld, and it seeped. Mine is working fine (I only run one on the left) for the last year, no drips when in the prime (off) position. My right side has a block off plate.

I would think that this would be one of the things that JBWeld would work pretty well for. As long as you let it cure the full time, you should be able to file and sand it down to get a smooth surface and a good seal. I may try it that way, of course it would take a good bit of it wouldn't it? Of course it would take a good bit of solder as well, I wonder which is cheaper?

[randy]

Instead of tin lead 60/40 rosin core solder, kester makes an aluminum solder. I'm doing this mod on my petcocks soon.