engine trouble....NEED HELP!!

[dirt286]

OK so this is how my day went.
Installed my new REV MAX rev boxand took the quad out for a ride. All was well until my throttle was stuck about half way open. Got the bike back to the house and pulled it apart. Turns out that the small "L" bracket that holds the air filter in place came loose, the air filter fell off the housing and the "L" bracket was sucked into the carb. It didn't look like anything was damged. Took the bike back out and it runs like crap. Idle is very very high and the engine is extremely loud. I cant even hear the exhaust, all I hear is motor. I cant describe the engine noise....all i can say is a lot of noise. Now it was getting more noisey for the past few weeks but thought nothing of it. Also when I kick it (kickstart) it wants to come back up. Also when I kill the motor I get a nice big POP. I need some help on what I have to do in order to get it running back to normal. Is it possible that the rev box had anything to do with it.....I dont think so because it was running good for the 10 mins before I broke.
thanks in advance

Where is the screw that held the bracket?

[ThumPIN_450R]

I had that happen many years ago when my 04 was almost brand new. The screw went in the motor and got wedged between an intake valve and the head stopping the motor. Something simalar may have happened to you with the screw or even the washer making allot of noise inside that motor. The head is pretty easy to pull off and inspect to see if thats a problem and would be well worth looking into before bigger trouble happens.

[dirt286]

Originally posted by TRX450R_Racer
Where is the screw that held the bracket?

Yeah I forgot to mention that in the original post. Its is not in the carb and it is obviously small enough to pass through and enter the motor.....Its not in the airbox either but there is that little drain in the bottom so hopefully it fell out of there.

I will pull it back apart tommorrow and inspect the head and the carb again, but why is the idle so high and why does it backfire when I kill the motor? maybe some problem with air/fuel ratio? Anyway any other ideas will be appreciated

[firefighterjosh]

Sounds like if you can not even hear your exhaulst that the screw is inside you engine.............SOMEWERE:scary:

[dirt286]

Ok I finally got around to pulling the bike back apart today. First thing I noticed that my air filter fell off again (zip tie method didn't work) so my first thought is that my air filter fell off a couple weeks ago which would make the bike louder and taking in all kinds of dirt which would make it run poor. So the carb obviously took in all kinds of dirt. The throttle valve ( i think that is what it is called, was binding up and I cleaned everything out and got it moving freely again. Also when I took the carb off originally and reinstalled, the hot start cable did not seat right which would also make it run like crap ( it was as if the hot start was always pulled open) What exactly does the hot start do, let in more air or fuel or what? Anyway got that back in right. Started the bike back up and played with the idle adjuster (black knob on left side of carb...this is the only one right?) Its idles good now, but I noticed when i put the choke on it is very high. I know it is supposed to be high but i dont think i remember it being that high. Or is it different when the bike is cold from hot? So bike isnt as loud as it was, it runs strong so i dont think that screw is anywhere in the motor, must have fallen out of the airbox. I still hear a little unwanted noise, but it may be my skid plate. It used to rattle like a mother but i put weather stripping around some parts to quiet it down, maybe it needs more. Also is it possible that my valves need adjusting. That haven't been adjusted since it was new when the HRC was installed by dealer. I had a honda accord back in the day and i adjusted the valves on that, which was pretty simple. When I tried t adjust them on the quad, the one side (believe it was the exhaust) looked just like the car but the other I couldn't tell where the feeler gauge was supposed to go. Anyway sorry for the long post but it was the best way to explain it. Thanks in advance for any thoughts