Which petrol should you use in your SR500?

There are over 150 members in the SR500 Club, and every bike engine is in a slightly different state of tune. There was a consensus view that, when released, Lead Replacement Petrol (LRP) was crap – just basically standard unleaded with the addition of some valve-seat lubricant which, unlike Lead, didn’t combust well. The result was harder starting and rougher cold idling, but for low compression engines, there wasn’t much evidence of pinging when the engine was at its normal operating temperature. These days, everyone loves premium unleaded (98 RON), e.g. Mobil Synergy 8000.