1980 gs1000e.... dramas..... yuk!!!!!!!!!!!!

[Guest]

hi guys,,,,well at the weekend i decided to drain my gs1000e tank it had about 15-19 litres... and was 98% unleaded so i wanted to empty the tank and check the vacuum petcock i think it has 52mm centre holes ...anyway when i put it on prime ,,,,nothing,,,,,, at all ... and and nornal even with nearly a full tank of fuel sitting there ,,,,i sucked on the vac. line and it sputtered .... so i removed the petcock and dropped the fuel into a larg funnel and then into a jerry can 20litre steel ... i noticed the only moving part is the flat diaphram and alloy round spiget with a light spring ... ,,, ,,there was no rubbish in it that i could see ........... what have i missed ....regards oldgrumpy

[tom203]

"......what have i missed ....regards oldgrumpy

You've missed having a working petcock! Is this petcock without lever (using screwdriver for deluxe prime feature) ? Maybe it needed to be burped harder in prime spot.
Bolt spacing was likely 50 mm centerline if so.

[Tom R]

The prime on mine doesn't work either. That style petcock uses a rubber check valve to hold the valve open after you initially create vacuum when you bump the starter. Turning the dial is just opening and closing an air bleed. If the rubber is degraded, you need to suck on the vacuum line to prime it.

[Nessism]

Tom and Tom are correct in mentioning the need for a vacuum pulse to open the check valve before fuel will flow. I'd go so far as to say you may need more than just a pulse. And if the check valve is leaking, you flat out won't have a prime. Only good thing about that model of petcock is they are cheap and readily available.