2004 400ex making wired clickin sound at start up!

[2004Ohio400ex]

sometimes when i start my bike up it makes a very werid sound almost like the motor is knockin but its brand new i bought it last year it was left over for 5200 out the door tax and title plus the 4 year wtty. i changed the oil and filter and now its clickin/knockin sound somewhat when it starts not all the time tho just once in awhile bought the oil filter from the same place i got the bike and i put 10w40 oil back in it and also i can't get my back breaks to work right after i replaced the ****ty *** pad's that came on it does that have somethign to do with the parkin brake cuz it didn't work when i brought the bike home ... any ideas plz help me out thx

also some other info i ran the **** out of it when i brought it home from the dealer ship i spent maybe an hour at the max babyin it the bike is stock ( cut out the baffles in stock exhaust )

[exboomer]

You didn't mention if it was under cold start up or not. You might want to check your valve adjustment. Are you sure the noise isn't a ping or pre-detonation? Make sure the gas is okay. Also inspect the spark plug and make sure it isn't cracked. If you have never changed the plug, change it. Or maybe your hearing the timing chain? Check the basics first, Good luck.

[brapbrap13]

start clutch.

[krt400ex]

u may need a valve adjustment. when ever mine starts to nock or click, i just get the valves adjusted and everything goes back to norm

[81 clark racing]

its your valves