engine noise

[redrabbit]

ok i have had my ex for a little while and it has made the same ticking noise ever since i have had it. i changed the oil this weekend and ever since i did it has been making this rattling sound, almost viberating sound, at a little more than half throttle and on. any ideas what it could be and could someone tell me the proper process to checking the cam chain tensioner. thanks alot

[bigredisb]

Have the valves been adjusted lately? Our 400's have a lot of valve noise especially if they have not been adjusted.

[racenaked_400ex]

first you should check every bolt on the outside of the motor. i say this because i had a noise coming from my motor that just turned out to be a loose valve cover bolt. also make sure nothing is wrong with your carrier bearings. noise travels through metal and my carrier bearings went out and i could of sworn the noise was coming from my transmission.

[redrabbit]

im not sure when the valves were adjusted last. so you say if the valves were adjusted then they may make some noise? and how do you know when you should adjust the valves. is it something that needs to be done regualrly?

[redrabbit]

im not sure when the valves were adjusted last. so you say if the valves were adjusted then they may make some noise? and how do you know when you should adjust the valves. is it something that needs to be done regualrly?

[kilgoja]

yeah i think you're supposed to have the valves adjusted every 100hrs or something...it says in the owner's manual...but these engines sound like a tractor engine anyways so u will hear the valves ticking...i've heard mine even when it was brand new but it's nothing to worry about

[bigredisb]

I agree they are are always going to make some noise. It is normal and if you just got the machine it may be normal noise that your not use to hearing. The other thing that can cause noise is the decompression mechanism that is used on the cam to aid in starting. Mine ticks and rattles on my new machine at idle. The valve adjust is easy and we have great instructions on the articles section I believe that I used to adjust mine. They are suppsed to be adjusted on the first 25hrs of a new machine and then 100 hrs after that I believe. Most skip the 25 hr one but its still a good idea to do it. If your machine has a afterarket cam in it it will also be louder because f the different cam profile and lash settings.

[jasonwayne222]

well lets think. anytime u have a problem u have to think back to what the last maintenance youve done to it was. well you changed the oil filter. maybe just maybe your dum azs put the filter in backwards and starved the motor for oil