Honda GN4 10w30

[Mikestib1_imp]

The last four Honda's I bought, a Grom, a Cbr250r, a CB 500x, and a Cb1100 , according to the owners manuals should use 10w30 motor oil with a MA 903 approval. I think the MA is a JASO rating for four strokes with wet clutches. For all of these bikes I bought either 10w40 Honda Gn4 or Castrol Actevo Xtra 10w40. Every one of them shifted harder than before the switch to the higher viscosity. I assume the original oil was 10w30. Think I'm going to believe Honda and use their 10w30. Or 10w30 Amsoil motorcycle oil. I've read enough on the forum about strange issues after the first oil change using non recommended auto oils. I use Rotella T6 in my scooter with no issue. The 1100 is going to Gn4 10w30 . It's Dino oil but maybe I've learned something. It's not expensive as I only change oil every 3500 after the first 600 miles, and the filter every other oil change.

[DAC]

Good plan. Used T6 in a VFR800 with no issue. CB1100 didn't like it as you describe.

[AzBob_imp]

I've so far used GN4 10w40 in my bike since it sees temps > 100*F. Works fine. I'm sure the T6 would be fine based on the complaint I read in this forum about its use and how my bike normally sounds when ridden in very hot weather (it sounds the way the gentleman described his bike did after filling with T6 leading me to believe this is totally normal).