1983 550es...petcock and fuel door. Pictures wanted

[BigD_83]

My new to me left side panel arrived on Friday, and I tried to mount it today.

For the life of me, I cannot get it to fit around the petcock that is on the bike, which got me to wondering if it is the stock petcock.

It looks like this one:

http://www.cmsnl.com/suzuki-gs550-es-3-ese-ef-esf-esg-83-86-usa_model16031/cock-assembly-fuel_4430043461/#.U8NlXPldVaE

but the '83 had the funny little fuel door.

The old side panel is pretty broken up around where the petcock knob sticks through the side cover, which supports my idea that someone has put on a petcock from a later model.



In addition, the "new" side panel does not have enough room for the large black knob to sit behind the fuel door.

I'd like to see some pictures of a petcock installed with and without the side panel mounted to see if there is something funny going on with mine.

[BigD_83]

Barring pictures of an installed petcock, I'd take photographs of an original petcock from a 1983 GS550E/ES/EF just to see what kind of handle was on it, and the relative size of the housing under the handle

[Griffin]

The '83 GS550E/ES used the standard style small handle petcock. Having to flip open the door and turn the tiny handle was slagged in the motorcycle mags, so for the '84-'86 models they did away with the door and went with the large knob style.

If you get a standard '81 and up GS petcock (like on the GS700E/ES), it will fit fine behind the little door, but be a pain to use.

[BigD_83]

Thanks, Griffin. That's what I thought, but I couldn't find any pictures of that setup anywhere. I have a couple of spare petcocks around. I'll have to see if I can make them work.

That enhances my confidence in my assessment that a PO chipped out the plastic to accomodate a newer style petcock, which is a vast improvement to sticking one's gloved hand into a small space to turn the lever.

My real issue is that the newer style petcock has a larger base, and an intact '83 panel does not fit over it, even without the aforementioned door. I guess I'll have to do a trick with the chipped panel for my collector plate application.

Even though I prefer the look and functionality of the newer design, I kind of like that the '83 is different. In the future, I'd probably go with the newer bodywork and petcock combination. Not sure how stringent ICBC would be, or whether they would consider it "period specific" enough to still grant the plate.

[BigD_83]

The '83 GS550E/ES used the standard style small handle petcock. Having to flip open the door and turn the tiny handle was slagged in the motorcycle mags, so for the '84-'86 models they did away with the door and went with the large knob style.

If you get a standard '81 and up GS petcock (like on the GS700E/ES), it will fit fine behind the little door, but be a pain to use.

I have to look at it again, but it seems like the body of the petcock is getting in the way of the cover, in addition to the handle being too large to fit behind the door. Looking at the (really poorly angled) photograph in the service manual makes it seem like the height profile is lower on the stock 550esd petcock; that might be what the PO encountered, and why they had to drastically chip out the sidecover.

How different are the petcocks you've mentioned internally and externally? Can the handle off a standard petcock be inserted into the body of a newer 550 petcock and vice versa? Just thinking about possible ways of matching up the parts I have on hand, before draining the gas tank for a swap or sourcing a new petcock.

[BigD_83]

I swapped in a petcock from an '83 650G, and it fits no problem. However, the fuel outlet and vacuum port point toward the rear of the bike. The vacuum nipple hits the frame, so it's back to looking for a petcock as short as that, but with the fuel outlet pointing forward. I know the 81 650G and 650E petcocks did that, but I have yet to track one down for less than $90.00.

Anybody have a functional one with which they'd like to part?

[Griffin]

I swapped in a petcock from an '83 650G, and it fits no problem. However, the fuel outlet and vacuum port point toward the rear of the bike. The vacuum nipple hits the frame, so it's back to looking for a petcock as short as that, but with the fuel outlet pointing forward. I know the 81 650G and 650E petcocks did that, but I have yet to track one down for less than $90.00.

Anybody have a functional one with which they'd like to part?

Take the back off the petcock and rotate it 90 degrees to see if it will fit in your frame. It should still work ok no matter which way the back is positioned.

[BigD_83]

Are you sure about that? I thought there was a set position to enable the vacuum to work properly? If not, that'd be a brilliant and low-cost solution for me.

[Griffin]

Are you sure about that? I thought there was a set position to enable the vacuum to work properly? If not, that'd be a brilliant and low-cost solution for me.

It's worked for me before. If you take the back off, you'll see that there is a diaphragm separating the back from the front where the positioning valve is, and a little spring pushing the diaphragm up against the valve. When the engine cranks, it pulls a vacuum on the intake side (including the carbs), which will pull a vacuum on the diaphragm via the vacuum line/port. This pulls the diaphragm away from valve opening, allowing fuel to flow around the diaphragm and down the fuel line.

Give it a try. Rotate the back so that your petcock will fit, then suck the vacuum line to put a vacuum on it and see if fuel flows out your fuel line.

[BigD_83]

Ok. Rotation successful. I see now that the diaphragm is fixed to the cover, and suction definitely actuates it. That's a positive.

Now I just have to see if the "uphill" flow is too much to overcome. With the angle the petcock sits on the tank, the back of the petcock is a little higher than the front. Even with the outflow towards the rear, I think there should be enough head pressure from the fuel in the tank to keep it flowing. We'll see how it goes.

Thanks for the input Griffin.

[Griffin]

Ok. Rotation successful. I see now that the diaphragm is fixed to the cover, and suction definitely actuates it. That's a positive.

Now I just have to see if the "uphill" flow is too much to overcome. With the angle the petcock sits on the tank, the back of the petcock is a little higher than the front. Even with the outflow towards the rear, I think there should be enough head pressure from the fuel in the tank to keep it flowing. We'll see how it goes.

Thanks for the input Griffin.

The back of the petcock is positioned that way on several GSes, including my beloved 700ES. My guess is that it is that way on the '83 550E/ES as well.