Anyone notice when U got the rubicon rev to the max u can hear a knocking sound? It was running 87 octane.

 

I doubt this is the problem unless you've installed a higher compression piston, but if the compression was upped, then you should runner higher octane gas. If not, the compression may cause the gas to combust before the piston reaches the top of the stroke, causing the knockin sound, which isn't good. Higher octane gas has a higher combustion rate, so it wont combust as early. Man, i can't believe i know all that, i'm only 16.

 

stock He bag's it to the max its kind of hard to notice but once u had a lot of miles on it.

 

It could be caused by the ignition system cutting out & in.......that's what the rev limiter does.

 

Or the valves need adjusting....?

 

Its not knocking. I'm running 11:1 compression and still use the cheap stuff with no knocking. You sure its not your valves?