There are people out there saying that when the oil lights comes on flickering it's already too late. My advice: do not ride the bike, find the cause. Start wit the obvious (enough oil, no leaks), then measure the oil pressure. My 1000cc engine pushed up to 160psi cold and settled to 20psi @ idle and 60psi @ 4000+ with the engine at operating temperature.
How to build a cheap and cheerful oil pressure meter in 5 minutes under $30:
- a 1 1/2" oil pressure gauge from your local hydraulic supply, 1/8NPT fitting, 160psi range, 270deg sweep (my preference)
- a tubing kit with 3ft-4ft of 1/8" nylon tubing and at least a 1/8NPT Male and one 1/8NPT Female fitting (e.g. EQUUS #9801)
- one adapter fitting M12x1.5 Male to 1/8NPT Female (to fit the original location of the OEM oil pressure switch)
- one 7/8" hose clamp
Oil pressure gauge on the bike: