Need help please with 50mm Petcock

[ericeder141]

Just picked up a new tank for my bike because the old one sprung a leak...

Old tank had a petcock where the mounting bolts were 44mm apart

New tank has a different petcock where the mounting bolts are 50mm apart

So my old petcock will not fit this tank and this tank did not come with a petcock... The research I have done has told me the petcock I need is 44300-47270 problem with that is all the petcocks I found do not include the on off tab with it... What am I do to? return the tank? Anyone have a source for a 50mm complete petcock?

[Guest]

Sounds like your tank is from an 80' model. Their petcocks have no on/off, it is simply controlled by vacuum. You can buy a new OEM one for about $75

[tom203]

This Florida guy sells them - as good as OEM , probably same factory in Japan, just cheaper

.http://www.georgefixs.com/1980-gs550...s1100-petcock/

[chuck hahn]

You put a small flat tip in the slot to turn it. Best way to PRIme the carbs is to hit the button and crank it over a few revolutions and then wait a minute. Then do it again. This will open the diapram and let fuel into the carbs but you wont need to keep cranking and drain the battery first. May take 2 or 3 "hits" but it will work fine after that.

[ericeder141]

Thank you guys, at first when I saw "tab not included" I was thinking I had to reuse the stock tab which i do not have...
i can live with going for the 50mm petcock, the only thing I dont like it there is no reserve function on it so I am going to have to re-rig a light back up for fuel level.

[Guest]

Thank you guys, at first when I saw "tab not included" I was thinking I had to reuse the stock tab which i do not have...
i can live with going for the 50mm petcock, the only thing I dont like it there is no reserve function on it so I am going to have to re-rig a light back up for fuel level.

Well, if you got a 80 tank there was no reserve on these. We just depending on the "cough" fuel gauge on the bike. Actually the gauges were fairly close to what they said. If you know your average MPG on your bike at any given speed, you should be fine.

[Guest]

Ericeder141,

I got burnt the same as you did....I bought a 1979 GS1000 resto project. I purchased a new OEM fuel tap for it (cost me a small fortune - nothing like $75!), only to find out too late that the new tap was 44mm centres but the tank was 50mm centres. The bottom line is I have a 1980 tank on what is otherwise a 1979 bike, and a surplus brand new OEM fuel tap in its' box. For a modest price I got an new aftermarket tap.

Like you, I really wanted a tap with the On/Pri/Reserve functionality but it's not to be.

[ericeder141]

My original 1980 GS750E tank (which has sprung a leak) has Prime, on, and reserve on it so I don't see why the 50mm petcock wouldn't... PS I found a new one on Ebay for $40 ill see how it goes. just want to get bike together and put some miles down... Winter ha been to long.

[Guest]

My original 1980 GS750E tank (which has sprung a leak) has Prime, on, and reserve on it so I don't see why the 50mm petcock wouldn't... PS I found a new one on Ebay for $40 ill see how it goes. just want to get bike together and put some miles down... Winter ha been to long.

The 1980 GS750E vacuum 50mm petcock did have prime, but no on, off or reserve, it is all controlled by the vacuum except for the prime. There is no lever with this particular petcock, you have to use a small flat bladed screwdriver to switch to the prime mode. This is for the State side 750s. I have 3-4 of these devil petcocks in my parts bin.