Needed Petcock 1980 GS750E

[rphillips]

GOSH, $128???...Knowing many, for good reason, don't (won't) try a rebuild. But for $128 vs. $20, thinking if I didn't like it, I'd got to give it a try.

[Sandy]

Wow....that would be $128us plus another $50us in shipping ....$250cdn to my door! Yikes

Cheap like borcsh. The one for my 1000 lists for around $430. Bet they don't sell many of those. Lol.

[Nessism]

GOSH, $128???...Knowing many, for good reason, don't (won't) try a rebuild. But for $128 vs. $20, thinking if I didn't like it, I'd got to give it a try.

Those leverless petcocks have a rubber diaphragm in the back cover that fails. When that happens, you don't have a prime feature anymore. Unless the rebuild kit comes with a new back cover, forgetaboutit.

[trevor]

Those leverless petcocks have a rubber diaphragm in the back cover that fails. When that happens, you don't have a prime feature anymore. Unless the rebuild kit comes with a new back cover, forgetaboutit.

My buddy that owns a Suzuki dealership and classic GS's himself has found me one with a lever that comes with an "adapter" kit to fit my GS....he's ordered it from MC....I'll keep everyone posted. Thanks for all the help fellas, much appreciated.

[rphillips]

Never had problems, other than the aggravation with those leverless petcock. Never a reason to have one apart. I will try to remember that info. about them. Hoping all works out Trev, Only neg. it won't be OEM, but for sure a better set up.

[Rob S.]

If there's no lever, how do you switch to reserve while riding?

[Nessism]

If there's no lever, how do you switch to reserve while riding?

There is no reserve.

[Rich82GS750TZ]

For anyone curious, this is an explanation of the 1980 petcock from one of the 1980 Service manuals.
They do a very poor job of explaining which slot position is Prime. It's my understanding that Vertical is the Prime position. Horizontal is the ON position.

[pdqford]

Thanks Rich,
Just a side note: I remember the GS Whisperer saying that vacuum needs to be applied to start fuel flowing when in the prime position.

When reading that last paragraph from the manual you posted above, with engine off, I don't understand how turning the valve to prime will creates a negative pressure in the "chamber" under the diaphragm.

Likewise, that caution where they say when starting the engine while in prime to switch to "on" immediately? I must be missing something as I don't see why.

[trevor]

There is no reserve.

I heard that they did that because they now had gas gauges? Like we know how accurate they are...lol

[rphillips]

Nobody trusted the fuel gauges, that's why the no res. only lasted only one yr.

[Sandy]

I heard that they did that because they now had gas gauges? Like we know how accurate they are...lol

Actually, after a bit of tweaking my gauge is pretty accurate. I thought they went to that fuel tap because on the 1980 1000E/S with CV carbs the old style gauge with the lever interfered with the carb caps and probably the same with the early 750/1100's.

[trevor]

Actually, after a bit of tweaking my gauge is pretty accurate. I thought they went to that fuel tap because on the 1980 1000E/S with CV carbs the old style gauge with the lever interfered with the carb caps and probably the same with the early 750/1100's.

Actually I think you are correct

[rphillips]

Well, for sure, the GS1000 E and S models had 3 changes from "79" to "80" in this area. Changed from VM to CV, changed from lever with res. to leverless without res, and moved the pet cock reward appx. 2". Thinking moving the pet cock back 2" is what made things work, I don't think either of the pet cocks would work with the CV carbs without it being rearward.

[Sandy]

Well, for sure, the GS1000 E and S models had 3 changes from "79" to "80" in this area. Changed from VM to CV, changed from lever with res. to leverless without res, and moved the pet cock reward appx. 2". Thinking moving the pet cock back 2" is what made things work, I don't think either of the pet cocks would work with the CV carbs without it being rearward.

#4. They also changed the mount spacing to 40mm from 44mm (IIRC ) so they aren't interchangeable between tanks.