Needed Petcock 1980 GS750E

[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.

 

[rphillips]

Yep Sandy, forgot that one, but give me a break that was 45 yrs, ago. I do remember the spacing changed, had no clue about the 40mm vs 44mm.

 

[dgates1]

FYI… those petcocks are being shipped again from K&L. The one I ordered will be shipped out from Cycle Recycle II on Monday. Maybe the other suppliers will start to show them in stock again.

 

[trevor]

FYI… those petcocks are being shipped again from K&L. The one I ordered will be shipped out from Cycle Recycle II on Monday. Maybe the other suppliers will start to show them in stock again.

Hey thanks! I did get one ordered but I checked with them today and they are getting it back to me...