18 XC300 possible detonation

[TGM_OFFROAD]

Hey everybody I have an 18 XC300 that I recently had to rebuild. I had a leaky left side crank seal that caused a lean condition and melted a hole in the piston. I just finished the rebuild and I am noticing what to me sounds like some detonation at about 1/8 to 1/4 throttle when holding it steady. I also notice it every once in a while when chopping the throttle. It is just a singular knock. I currently am running with an RK tek head supposedly set up for 91 octane, lectron carb which is adjusted slightly rich with a 4-2 metering rod. I am really paranoid and don't want to have to rebuild my motor again and am kind of lost on what to do other than run race gas which I havent tried yet. Is this possibly caused by ignition timing? I didnt see a way to easily change timing on the bike and there is nothing in either manual about it.

 

[Greatdane]

Did you use a thinner base gasket when you did your top end? I pit the thinnest base gasket available in mine to boost low end grunt, but noticed a slight occasional detonation when letting of the throttle.

 

[TGM_OFFROAD]

The gasket kit I ordered only had one base gasket and I am unsure of the thickness but it was the same as far as I could tell as the original one I removed

 

[arminhammer]

Pipe bang is a rich condition not a lean one.

 

[nknudsen]

I've had detonation like sounds on deceleration before. I tried jetting, needle position etc.. It ended up that the slide was set too high with the idle screw. Moral of my story is get the bike to idle with the slide as low as possible.