I was told early on that the old Triumph V-twin is notorious for a weak oiling system. Therefore change oil frequently and always keep it topped off. Do not use additives and be especially aware in summer when idling frequently as this engine can run very hot.I have an aftermarket pressure guage and when the engine is first started it shows over 60psi at idle. Once it is warmed up and the oil viscosity drops off it only registers 30-40psi when RPM are at running speeds and 5-10Psi at idle.I use 5W 20 Valvolene