[Charlie_nelson40800]

For the past couple months my 04 400ex has continuously ticked. I replace timing chain timing a month ago and the tick continued. Thought it was stretched so I replace it again today and still ticks. I've inspected almost everything. Gaskets are all good, tensioner is good piston is good, there's nothing rattling in the motor like bolts or nuts.

The ticking increases in speed when i give is throttle. I know that usually means its the chain but the chain is 100% ok nothing wrong with it brand new.

I need some advice on what it could be, I heard that the decompression pin could cause ticking on 400ex's, it's a stock cam and the decompression pin sticks up. I also heard that some 400's just tick from the showroom at the start of their lives and there's no way to stop it, please give me a some advice on what I should do or check. Thanks for any help.

 

[SlammedRanger]

You obveously adjusted the valves when you changed the timing chain i would have to guess. When you say the tensioner tests good. There is no way to really test them besides put a new one in and see if the problem goes away. I have seen countless ones that check out perfectly fine seem to work perfect but are bad still. I had a decompression mech be noisy on me before but would only do it at cold start up then would go away never had one rattle all the time. I would bet its the timing chain tensioner. Could also be the secondary rocker arms or shafts or cam and rocker arms excessively worn and making noise.

 

[Charlie_nelson40800]

You obveously adjusted the valves when you changed the timing chain i would have to guess. When you say the tensioner tests good. There is no way to really test them besides put a new one in and see if the problem goes away. I have seen countless ones that check out perfectly fine seem to work perfect but are bad still. I had a decompression mech be noisy on me before but would only do it at cold start up then would go away never had one rattle all the time. I would bet its the timing chain tensioner. Could also be the secondary rocker arms or shafts or cam and rocker arms excessively worn and making noise.

Ok. I gotcha. I know the tensioner works correctly though i swapped it with my neighbors 400ex and the ticking continued still.

 

[SlammedRanger]

You obveously adjusted the valves when you changed the timing chain i would have to guess. When you say the tensioner tests good. There is no way to really test them besides put a new one in and see if the problem goes away. I have seen countless ones that check out perfectly fine seem to work perfect but are bad still. I had a decompression mech be noisy on me before but would only do it at cold start up then would go away never had one rattle all the time. I would bet its the timing chain tensioner. Could also be the secondary rocker arms or shafts or cam and rocker arms excessively worn and making noise.

Ok. I gotcha. I know the tensioner works correctly though i swapped it with my neighbors 400ex and the ticking continued still.

I would be pulling the valve cover then and checking for any play in the rocker arms, or secondary arms. And making sure the cam profile is smooth on all 4 lobes and that the rocker arms contact surface is smooth as glass. Any abnormal edges forming anywhere on either one will make it impossible to adjust valves correctly and will make the topend make noise. The reason people say that some tick from the factory is because all hondas have a slight tick. But the fact it gets faster the higher you rev means it isnt just the honda tick. Its something worse. Because the honda tick only really happens at low idle or light throttle and goes away in higher revs. I always judge it this way and im sure there is a more proper way to test it but i listen to the engine at idle with my helmet on and if i can hear the rattle i adjust the valves. If i cant hear it i leave it alone.

 

[fishfiles]

unbolt the tensioner from the jug , leave it loaded ( don't retract and lock it ) and try to push it back into the jug , if it goes in flush against the jug then the chain is loose or the tensioner is not holding ------------- could be the tick is coming from the wrist pin / piston connection point , worn out valve guides or rocker arm

 

[TRX2fiveO]

An increase in ticking speed as you increase throttle could be incorrect valve lash or a bad decompression mechanism? If you are running an aftermarket camshaft such as a Hot cam, Then their lash is .001 more than stock. This will cause a tick especially when the engine temps rise. I'd set the lash to OEM spec .004 intake and .005 exhaust with a tight drag on the feeler, tight enough so that you can insert it back after you pull it from between the valve and tappet.

 

[Charlie_nelson40800]

Ok thanks i will try this

 

[dilligaf29]

mine made a crazy ticking noise found out it was my bad decompression mechanism changed out to hot cam all better now

 

[Charlie_nelson40800]

mine made a crazy ticking noise found out it was my bad decompression mechanism changed out to hot cam all better now

You mean the decompression mechanism on the cam? Or the decompression spring?

 

[dilligaf29]

the mech on cam it was faulty and smashing the pin down ever time

 

[TRX2fiveO]

Ok thanks i will try this

Keep us posted.

 

[Charlie_nelson40800]

the mech on cam it was faulty and smashing the pin down ever time

hmm. I mean the part in my cam that is above the decompression pin spins on the cam in in one direction only. Is it supposed to? I kind of described it badly lol.

 

[Charlie_nelson40800]

Ok thanks i will try this

Keep us posted.

Cant work on it till monday but will do. I Hope i figure it out!

 

[Charlie_nelson40800]

Slammedranger the rocker arms have no play in them so thats not whats causing the tick. They're all smooth as glass like you said they should.

 

[SlammedRanger]

Hmmm. You tried a different tensioner and that didnt help. So my next place i would be looking is the auto decompression mechanism. You adjusted the valves just like trx2five0 said right?

 

[Charlie_nelson40800]

Well no i didnt because i have a stock cam. The valves are adjusted to the stock cam right now. And if the valve adjustment was off wouldnt my atv smoke? Mine doesnt

 

[SlammedRanger]

Anytime you pull the valve cover off you 100% need to adjust the valves. And valve adjustment has absolutely zero to do with smoke. When valves need adjusted they make ticking noise. If they are to tight it will be a bear to start if it starts at all.

 

[Charlie_nelson40800]

Ok i gotcha. Thanks alot i will adjust them later today.

 

[SlammedRanger]

No problem! Hope its that simple that would be about the best case scenario!

 

[Jkisul]

Hey guys I know this issue has been cover over n over again lol. I just got this 2004 400ex. Finally got it runnning and idling it has the tick I adjusted the valves multiply times .004 intake and .005 exhaust if I’m correct. The timing chain n guides are good checked for metal in the oil filter all looks good. Now the only thing I notice is the guy who had it had a hot cam in it and then put the stick cam back in and he lost the compression spring that’s suppose to be in the head I guess not really sure but would that cause a tick. Thanks and the tick is steady doesn’t very when giving it throttle at all just a steady tick. Thanks again