yer it could have to be pretty bad though... do you have a bash plate??? i know when i first put me bash plate on it makes the tinnyest noises sound much louder and worst than they really are... make sure the exhaust bolts are tight and all the other bolts
if you get it apart and it should have sum movement.... like less that a millimetre.... if it has more and feels really loose then you need to tighten it... if you get a business card and cut a strip off it then its pretty close to the rite distance... a make shift feeler guage if you will...
If you've replaced the engine with another why don't you check if you have put the exhaust gasket in. It's usually a little copper looking gasket. If you have forgotten to put that in the ticking noise could be coming from there.
It's usually just a little copper gasket that sits between the end of the pipe and the exhaust port on your engine. It's pretty easy to check. Just remove your exhaust and check if its there or not.
ROFL, Sidney your laugh is freekin awesome.. your brothers a dud too, if your running in your bike .. maybe u shouldnt be riding in like a 5x5m area in first and second gear.. Just a tip =]
If you have changed the engine then I would imagine that the gasket is probably still in the old engine if you have neglected to put it in the new one. I'm sure it wouldn't just dissapear. Then again.....
oh and sidney did u say your throttle was accelarating by itself if you did your bars are to far back and you putting strain on the cable mine did that when i got my tapers put them a bit forward and it doesent do it now.