Octane….dang it

[K447]

I just remembered this thread from 2019

Knock sensor: Using 87 (or 89) octane gasoline in Yamaha SVHO engine

A salient point from that post is that once the Yamaha SVHO ECU determines the fuel quality is below threshold (engine knock persistently detected) it changes the ECU operating mode until the engine is shut off. Until the engine is shut off the ECU will limit throttle opening percent and reduce ignition timing.

It is a presumption on my part but I suppose the Riva tune(s) would implement a similar strategy when engine knock occurs due to insufficient fuel octane for the engine operating conditions.

[John F.]

Klotz KL602 is the quart version of the KL628 gallon. Both use MMT, a lead substitute, and safe for O2 sensors. I buy/use KL628.

Klotz technical services email response.

[WaterDR]

Jesus told me the low octane turn is good for anything under 91. However, there is some confusion at the marina. Being told the fuel is now 91 Octane. Makes me wonder….either way, I can get 92 if I want but need to pull the machine which defeats the point of having it at the marina. However I will pull it from time to time to clean and service it.