400ex problem need help!!

[muddzilla94]

my 400ex started ticking very loud today after about a hour of riding, it only does it at idle and not when gave gas. so i need some help, throw me some ideas about what you think it is.

[honda400ex2003]

i think it needs the valves adjusted but i will think about it some more. this is just the first thing that comes to mind when "ticking" is involved anywhere around the motor. lol, steve

[muddzilla94]

thanks, im going to adjust them tomorrow and see if that helps. I think it might be the timing chain cause it is really loud at idle

[honda400ex2003]

could be that also check and see if you can get a better sound of where it is coming from with an extension for a socket or a screwdriver held to your ear. the guides may be wore or the tensioner is not keeping tension on it. i have seen that before too. i would check that to see if it is working correctly by moving it in and out with a small screw driver while it is off. if anything it is the easiest to check since it just unbolts with 2 8mm bolts. if the guides are wore the head has to come off to change them. the cam chain could also be stretching too and if you do the guides you should do the cam chain. i would do the crf450 cam chain since it is a better and stronger than a stock 400ex chain. just a few ideas and such to help you out. i think the most prevelent is the valves then the tensioner, then the chain, then the guides. steve

[muddzilla94]

thanks man, i forgot to say it has a brand new head straight from honda due to mechanic forgetting wrist pin and it only has around 100 miles on it

[honda400ex2003]

so the whole machine has 100 miles on it or just the head? if it only has 100 miles on it then adjust the valves since it probably wore in the rockers and such and has some play in it now and you should be good to go. the rest should not be wore out yet. steve

[muddzilla94]

just the head, now the bottom end is a different story it has quite a bit of mileage lol

[honda400ex2003]

lol, then i guess i would still check the rest. i have around 6000 miles or more on mine without the guides going bad or the tensioner being messed up so the odds of that stuff going bad is slim but not unheard of. i have put a tensioner in my dads rincon with only about 4000 miles on it. lol, steve

[killer400ex]

you could jus try seeing if you can tighten the tensioner, that might solve the problem, if thats not the case then tighten your valve clearances, i would do that b4 i took the the valve cover off, then i would check the chain and tensioner, and then i would check the valve guides by wobbling the valve stems, but thats the order i would use, and remember that if you want to change your chain that you have to take the right side cover off to get to the clutch, and then you would take the clutch out so that you can remove the cam chain

[muddzilla94]

thanx for the help guys it was the tensioner and i ordered one for it today so it will be back running again soon.

[chillytater]

mine 400 was makeing the same noise before i tore it down for a 416 mod so after reading your thread i started looking at mine and was wondering how did you know it was bad

[honda400ex2003]

they dont move in and out like they are supposed to. if you turn it in and it does not go back out you know it is bad. i guess that is how i checked mine. you should not be able to just push it in either so that is another way to check it. there is actually a key that goes inside it to turn it in and lock it to install them. then when you pull the key out it adjusts itself to the right tension on the chain and will not go back in. steve

[chillytater]

well with mine i can squeeze it in my hand and it goes in but hangs up half way on its way back out

[honda400ex2003]

it is messed up then. lol, that is not supposed to happen. lol, steve

[chillytater]

and it take it you get take these apart you have to buy a new one for 65 bucks

[honda400ex2003]

yeah they dont come apart so you get to buy a new one. it sucks steve