1979 GS550E Petcock Issues

[Longy515]

So my petcock is giving me fits. It leaks when the engine is shut off sometimes, sometimes it stops letting fuel through while riding and leaves me stranded, and I'm trying to figure out what parts I need to order. I have rebuilt it using an ebay rebuild kit, however, the kit did not supply the replacement diaphragms. This is my petcock: http://www.bikebandit.com/1979-suzuk...1489#sch286846

First, how any diaphragms do I need? Everything I have searched for on ebay only shows one diaphragm available for this petcock, however, mine currently has 2 in it and I'm wondering if one of them isn't necessary.

Also, does anybody have a suggestion for where to buy the correct diaphragms?

[tom203]

AS you have already found out, rebuilding petcocks is IFFY- should only be done if there are no other options, like brand new petcock.
What is the mounting bolt spacing on this 79 petcock and which way do fittings face?

[Longy515]

I haven't had a chance to measure the mounting holes yet, but I just found the part number. It is FUEL COCK ASSEMBLY 44300-47011 The fittings face inward with the vacuum hose fitting facing up and forward. See the picture on this link: http://www.ebay.com/itm/NOS-Suzuki-1...69c0d4&vxp=mtr

[tom203]

That's quite a petcock! Before you take off and measure, contemplate whether you could use one that had both vac and fuel fittings facing rear without obstructing something.

[Longy515]

There is plenty of room, do you think a simpler petcock like the one below would do the job assuming the mounting holes are the same?

http://item.mobileweb.ebay.com/viewitem?itemId=310525654675

[tom203]

There is plenty of room, do you think a simpler petcock like the one below would do the job assuming the mounting holes are the same?
http://item.mobileweb.ebay.com/viewi...d=310525654675

That's the dreaded 1980 leverless petcock- to be avoided if at all possible, as it has "unique" features. Lots of the early 80's petcocks with levers have a mounting bolt centerline spacing of 44 mm like this guy
http://www.ebay.com/itm/SUZUKI-GS450...K/360676185759?_

[Longy515]

So I measured and the mounts are 44mm center to center. The ebay link you posted seems like a really good price. Do you think that's my best option?

[tkent02]

Call Z1 Enterprises, they sell good petcocks for about that price.

[tom203]

So I measured and the mounts are 44mm center to center. The ebay link you posted seems like a really good price. Do you think that's my best option?

That seller ( like Z1 also) has two slightly different petcocks with the 44mm bolt spacing. The difference is the spot where reserve kicks in - the unit I linked has a low reserve spot (i.e. you don't have much reserve); the other has taller filter/tube so you can go farther on reserve. I wanted the low reserve spot,so I bought that one.