Guys,
Sorry if this is an obvious question, but I want to understand how the petcock operates on an '86/'87 model.
The petcock is vacuum-operated, and the electrical connection is only for the simulated reserve.
So if the tank is removed from the bike and the wire for the reserve valve is disconnected, should fuel leak from the petcock or not?
From what I understand, until vacuum is applied, no fuel should flow. Right?
Thanks. :morning1:
Correct on the 86/87 model it should not flow any fuel until vacuum is applied. If it is flowing fuel the petcock is bad.
The 84-85 has a prime function which will flow fuel when the selector switch is in the prime position but in the on position it should not flow fuel until vacuum is applied.
Quote from: RPM - Robert on February 24, 2026, 10:35:03 AMCorrect on the 86/87 model it should not flow any fuel until vacuum is applied. If it is flowing fuel the petcock is bad.
The 84-85 has a prime function which will flow fuel when the selector switch is in the prime position but in the on position it should not flow fuel until vacuum is applied.
Thank you Robert.
Quote from: MarioR on February 24, 2026, 11:01:44 AMQuote from: RPM - Robert on February 24, 2026, 10:35:03 AMCorrect on the 86/87 model it should not flow any fuel until vacuum is applied. If it is flowing fuel the petcock is bad.
The 84-85 has a prime function which will flow fuel when the selector switch is in the prime position but in the on position it should not flow fuel until vacuum is applied.
Thank you Robert.
I recently had to get a rebuild kit from RPM for me 84 because my tank started marking its territory when I took it off the bike. Put on the rebuild kit and it seals it right back up.