[Rio]

On the last leg of my tour yesterday, the only unleaded gas I could find was a higher octane ("95") than what is usually sold here in Indonesia. I'd been riding hard for about 300 km that morning, had an hour break on the ferry, then refueled. About 40 km after refueling I thought I could hear the engine's pitch drop a note or two, sounded deeper. At first I even thought I might not have put the air filter back in properly but that didn't make sense. Today it sounds 'normal' again.

Someone I know said it was a "honda thing" but I'm not sure it wasn't just a "fatigue thing". Curious to know if anyone else has experienced that? Never had anything as noticeable as that with any other bike.

 

[Alexander]

I've never noticed something like that, not with 95, 98 or 100 Octane

 

[Str8Psyko]

I may be completely off with this but were you riding uphill more on the trip back? Making the engine work harder will change the sound of the engine. If you are on a long stretch of road flat and it changes pitch I would be looking at dirty fuel injectors or fuel. As long as you don't consciously change the throttle.

 

[Harsh_66328]

From past 2 days Ive noticed my engine sounding a bit deep and it feels like when you have low pitched bass sound added. I dont know if its really sounding like that or maybe my mind wants to hear sounds like that.