i searched and this seems to be a common problem with 400exs.
mine only ticks at idle. ive heard answers from cam chain, to valves, to rocker arms, to the exhaust not fitting right. ive heard a lot of things. i wanna know the right answer. lol i hope its the valves, my dad is an experienced mechanic and can do that himself, so i dont need to spend any money. lol.

any ideas on what it could be?

i also heard its "normal" for a 400ex to make this sound and to not to be worried.

 

The valves should first be adjusted ...

 

right, that was first on my checklist, and if that doesnt work? whats next?

 

If it's not the valves change the timing chain. It's not that hard if your dad is experienced. More than likely it's one of those two things.

 

i bet it is one of those two , if u got a stock cam shoot for .004 clearance , i dont no what to tell u if u got a stage cam , i havent messed with one of them yet

 

my 400 is doin the same thing it has a loud ticking noise but im sure it ticks all the time no matter if its ideling or goin fast how much damage would driving it do

 

Did you remove the phillips head bolt from the center of the cam chain tensioner , and try turning the tensioner screw with a small flat blade screwdriver to tighten the cam chain ... If the noise gets quiet you may need a new tensioner if the chain won't tighten anymore you may need a new cam chain ..

 

i heard with the stage one cam that it should be 5, 6.