ok i have a 99 f4 after a stunt show that i did 2 weeks ago i started hearing a Trrrrrrrrrrrrrrrrrrrrrrr sound coming out of the engine and it increases when i accelerate i think it started happeneing after i did a 12 clock burnout for a prox 10 secs , the sound is getting louders by the mile , yesterday after an hour stunting the oil light started blinking for a couple of secs !!!! i asked a mechanic he said u need to change the engine chain......
wat the hell is happeneing?

 

cam chain tensioner is crap, or one of your rod bearings is spun.. has it lost alot of power? or backfire more often etc? if it hasn't lost any noticeble power then its most likely cam chain tensioner. also get your bike to running temp and drip some water on each tube of the header, might have fouled a plug or two..

 

so its not a knock. you can check for a bad cylinder by removing the ignition coil one at a time while theyre still running and listening for a change in sound.

and im suggesting this based on the fact the oil light came on.

sound that goes away when spark removed= spun rod bearning
sound that doubles up when spark removed = wrist pin