top end rattle?

[quadrdr77]

have a 05 450r with ported/polished head, new valves, web 208/921 cam cp 13.5-1 piston and a new timing chain. at idle there is a noise coming from the topend of it and for the life of me i can not figure out what is causing it. all motor work has two races on it including a new crank and crank bearings. the noise will come and go. i've ordered a new timing chain since the one that is in it has about 10 races on it and has gotten hot once bc i pulled the best dumb *** move ever and stuck the oil filter in backwards which caused the complete rebuild. any help would be greatly appreciated. noise sounds like its coming from under the valve cover. have checked valve springs and all and can not find what may be making this rattle.

[xcracer416]

decomp rattle?

[quadrdr77]

it very well may be decomp rattle but not sure. ordered a new spring for it but wont be in until thursday. mine isnt broke but for $1.63 its worth a try.

[OTMTRX]

What did you set the valve clearances at? 0.006" In and .009" for the Ex. works well with the 208 apparently, my 242/812 rattles at .011" Ex, but at 0.009" it just quiets down noticeably.

[DnB_racing]

take as much plastic off as possible and make sure it still does it,
if that doesnt narrow it down

go buy an automotive stethoscope and it will help you pin point the exact location of the noise


you can use a long screwdriver and put it to your ear, but a stethoscope works better

[quadrdr77]

dnb i jave a stethascope for automotive use and the quad is stripped all the way down far as plastic goes and the noise is coming from the cam area,

otmtrx i believe my valves are set a little bit looser than that, all four valves are brand new with two races on them. i checked the clerance but cant remember what it was, i'll go home and set them to 6 and 9 tonight and put the new decomp spring in and see what happens.
thanks for all the advice guys

[sdxp787]

did you figure your noise out? I ask because I have the same issue with my 07 450R. Mine goes away when you hold the brakes and load the motor.

[quadrdr77]

Yes i figured out the noise. It ended up being a few kinks in the timing chain that was causing the noise. the timing chain that was in it only had a few races on it and thats the reason i didnt suspect it as the cause.