Weird Noice??

[WheelieMan4]

I went riding on saturday and towards the end of the day i started to hear a strange rattling noice. I checked the heat shield cuz i thought that might be it, but its tight...so i have no idea what is going on...anyone have any idea on what the heck it is? i think im gunna have to take it in...:scary:

[quadwunner]

if you have the pro peg nerf then it could be those rattling.
one of my friends has a 400ex that does that..
start up ypur bike and then hold your leg down on it and see if it stops.
it could also be a skidplate or anything like that.

[EXevan91]

look at all your motor mounts one of them might be comeing loose.

[Travis712]

Well for one its noise, and for two, just take out some wrenches, allen wrenches, and screwdrivers and go over anything you can reach.

[sakirocket28]

Just grab the tools you're gonna need and go from the front of the quad all the way to the back, and check every bold and fitting.

[WheelieMan4]

ok, well can someone post a close up pic of the right side of the engine. because when i looked at it, i saw a gap somewhere, but i can really recall where and what its even called...

[Travis712]

http://atvrideronline.com/quads/100_0308_racer02_s.jpg

that what your looking for?

[smitht316]

i was riding down at the dunes last weekend and at the end of the day my quad started making a god awful noise and i thought it was my tranny and when i got home and inspected, it turned out my axle bearings were shot. it made more of a clunk then a rattle but still a shot

[94F450SD]

do you have the quiet core or spark arrester in the muffler?in my HMF the spark arrester and the quiet core rattle like hell.

[Iliketogofast]

Take em out then.

[94F450SD]

i usually do but that hmf is freakin LOUD!!im gonna get a piece of gasket paper from the parts store and cut a piece to go in with the core or spark arrester to keep it in there tight so it wont rattle.

[WheelieMan4]

yea i do and i could hear it the whole day, or like whenever i got on the gas at all....but this other rattling noice was like second gear and up...and only like right when ur getting ready to shift, so high rpm's...??

[WheelieMan4]

Well...i had a friend listen to it and he said it sounds like my valves? could i have fried them or something? or do they come out of adjustment that easily?? thanks alot

[am_muscle]

My 02 400ex also makes a rattleing noise at high rpms, I checked valves, tightened the exhaust and all the bolts around the engine and it still does it. Has a FMF powerbomb header and powercore muffler. I also have a friend with an 04 400ex and it does the same thing. So I'm just gonna ride it and if it gets worse I guess I'll look into it further.

[bwilson624]

My 400 rattles at high rmps also. I've checked everything that I can, even took the heat shield off, and still can't find anything. It still runs fine though. I guess I probably need to take it to my dealership. Oh well, I will when I get the money.

[Iliketogofast]

Originally posted by WheelieMan4
Well...i had a friend listen to it and he said it sounds like my valves? could i have fried them or something? or do they come out of adjustment that easily?? thanks alot

It probably is the valves, they need adjusted like once a month. If you don't they start to rattle. If you keep riding like that you might damage something.

[WheelieMan4]

My friend told his brother in law and he said that it sounds like there is dirt in my cylinder...i dunno, i guess i will take it in and get it fixed...