prim position on fuel valve

[oldbiker]

My 1980 gs 850 gl has a vaccum operated gas valve with no manual lever exccept for a prim position that requires a small screwdriver to turn ,but turning this has never allowed fuel to pass through to the carbs.I put on a new valve but it too does not work.I took apart the old one and cannot see how this works.What gives?

[hillsy]

You should have ON, RES, PRI on the tap. PRI should flow fuel at all times, ON and RES should only flow when the engine is running.

Post a pic of your tap.

[Nessism]

When in doubt, check the service manual.

Your petcock has a check valve inside, and a pulse of vacuum is needed after you turn the small slot to the prime position in order to get fuel to flow.

[Rover]

Suzuki made a petcock in 1980 with no reserve.

You should have ON, RES, PRI on the tap. PRI should flow fuel at all times, ON and RES should only flow when the engine is running.

Post a pic of your tap.

[Steve]

My condolences on your "dreaded '80 petcock".

Nessism has it right. All the others will flow freely when the petcock it turned to PRI, but the '80 model (thankfully just one year and just on the L models, I think) requires just a pulse of vacuum to get it started. Once it is flowing, it will keep flowing until you turn it to RUN or the gas runs out.

.

[Kaiser Sosei]

My condolences on your "dreaded '80 petcock".

Nessism has it right. All the others will flow freely when the petcock it turned to PRI, but the '80 model (thankfully just one year and just on the L models, I think) requires just a pulse of vacuum to get it started. Once it is flowing, it will keep flowing until you turn it to RUN or the gas runs out.

.

The "E'" models as well.

[Steve]

The "E'" models as well.

My condolences.

I was dreading receipt of one of those evil contraptions when I got my '80 850G, but was ecstatic to find that it was "normal".

.