Detonating pretty bad

[evaneyeball]

My bike was running fine all day and would wheelie whenever i wanted then we got out to the bigger hills my friends banshee was having problems so we headed back and mine started to act a little funny I thought I lt was getting hot cause its a 350 ceo with a stock radiator and new paddles thought that was the problem. Got back, worked on my friends banshee then I thought I'd check my plug and it was a little loose. I didnt think much of it just cleaned it off and put it back in and tight. When it was out it looked perfect. Up to here it had been running fine all day just a little funky the last like 10 minutes but once I tightened the plug it did not want to start and when it did it sounded horrible and when I out it into gear it either died immediately or didn't have enough power to move itself. So could it have been something to do with the plug cause thats all that changed. I thought it was my reeds cracked again but they look fine (I pulled them off) when I get home I can check my timing and I have a extra cdi and coil I can try but I dont k ow why that would have gone out. My carb was leaking out the overflow only when it wasn't running but before it started I haven't touched that

[The norm]

I would do a compression test.

[Michael88R]

Double check your timing with that hpi ignition.   Too much advance can detonate. 

[evaneyeball]

I did a compression test it make 180 psi and last time I did one it was like 220 if I remember right. I did a leak down test it passed 10psi for 10 minutes, I called the napa I bought the gas from just to make sure that the gas wasn't years old or something crazy, I also did check my timing and it was exactly where I set it. Then to get a better look at everything I popped the head off and it all looks fairly decent for detonating. Should I pull the cylinder since I'm this far and check my rings because I'm fairly sure thats why the compression is down, the sides of the piston looked good for what I could see through my intake and exhaust ports. And I'm pretty sure that either my cdi or coil went wich ill swap out once I get o rings, I already have a extra of both

[2ndmoto]

I don't see any noticable damage. But the compression drop is a concern. Do you have another gauge you could try? Were you holding the throttle wide open when you were kicking during the compression check?

[broken1]

What plug are you running?

[evaneyeball]

i try to run b8es's but all i could find for a new one was a br8es cause i left my stash of b8es's at home. so the first day was b8es the second was br8es