How hard is it to get to the timing chain

[gpd005]

My 416ex is making a nasty ticking noise when i'm on the gas. It sounds normal while at an idle but when your on the gas it sounds real loud! I've adjusted the valves and they are good so i think it's the timing chain tensioner (SP?) How hard is this to get to? Am i going to have to tear the whole motor down to get to it? I'm just not sure where it is actually at on this motor. Any help or somewhere that might have a diagram of the motor would be great!
Thanks!

[440_Turtle]

You can do it your self if you have a manual. I just did mine and its really a piece of cake. took several hours but you can do it with basic tools in your garage. if its the cam tensioner thats easy to replace. its on teh back side of the jug. if you on teh right side of your bike its that piece in teh back side of teh cylinder. two bolts and it comes out. you will need to remove the cap and compress with asmall flathead screwdriver the spring b4 you install a new one.

so to replace cam chain you will need to do the following.
-Remove rocker cover, remove cam shaft, remove clutch cover, remove clutch basket, then slide off old chain and replace with new chain. Now the tricky part. youve gotta get the chain up to the head now. I used a modified coat hanger but a piece of string dropped in and tied to teh chain shoudl do the trick also. then just reinstall all parts. All this can be done with the engine still in teh frame, you will just need to remove gas tank and plastics. hope this helps you make up your mind.

[gpd005]

I think the first thing i'm going to do is replace the head gasket. It looks like there is a leak in it. I have read that it can cause the same noise that i'm hearing. That would be a lot easier!

[440_Turtle]

yeah but you gotta look at it this way, your bike is almost 6 years old now and your been running a 416 which im sure you havent been babying, these chains stretch and break and when they break it isnt pretty, its cheap insurance

[gpd005]

That's a good point! Maybe i should just do the chain and tensioner and gasket while i'm doing it! AAGGGGGGGHHHHHHHHH

[nakomis0]

You can check the chain tension by only removing the valve cover.

6 yrs does sound like a longtime for a cam chain.

[NacsMXer]

Originally posted by gpd005
That's a good point! Maybe i should just do the chain and tensioner and gasket while i'm doing it! AAGGGGGGGHHHHHHHHH

Yep, and make sure while you are doing it to upgrade to the CRF450 timing chain. I believe the 2002 model is the one you want. 25 bucks from Service Honda and much beefier than the standard 400EX timing chain (far less prone to stretching). I wouldn't want to do all that work just to put the same chincy 400EX cam chain back in there ;)

[Glamis400ex]

I am right in the middle of doing this very thing. First and foremost....BUY A MANUAL. It's not hard at all and can be a little intimidating your first time. If you are already down to replacing a head gasket, you can definately do a cam chain.

My 400ex is a 1999 and I have not babied it. I've had a 416 in it for 2 years and would have gone 1 more season if it wasn't for a leak so I figured I'd swap it out since I was already THAT far into the motor.

Glamis

really easy to get too

[400exredrider]

the hardest part will be re assembly, make sure you get everything in the right spot, and get the timing correct,, dont put your cam chain tensioner in until you have the chain back on both of the sprockets then make sure the dots are lined up for timing

[DieselBoy]

changing the tensioner isn't hard at all, 5 minute job. however if your chain is loose/cam guides defective, you will need to remove the jug (cam guides)

[WheelieMan4]

ive only had my 400ex for a year now, and my cam chain needs to be tightend/replaced already...i called my dealer and they said that it will be covered under warranty, so im just gunna have them fix it for me...saves me the trouble of messing it up

[DieselBoy]

you runnin a stock cam?

[gpd005]

Well, i tore it apart this weekend the cam chain seems to be tight and doesn't appear to be worn very bad. I took the tensioner out and it is still holding pressure on the guide? Anyone have any suggestions for me? It's still making a loud tick/banging sound when i get on the gas. Not when it's ideling?????

I've adjusted my valves and i yes i do have a web cam in it?

I'm lost at this point!

[Wheelie]

Lower con-rod bearing failure?

[gpd005]

Man i sure hope not! I ordered a complete gasket kit and i'm gonna try that before i go much further.

[DieselBoy]

did this noise start suddenly? or was it getting louder, gradually? i dont think a gasket is the problem, it sounds like something mechanical . . . when the jugs off, look at the piston/connecting rod.... does the piston move up down/radial play? it's possible the piston shrunk and it knocking around in the cylinder, or a bearing/rod is bad..... keep us posted :)

could it be spark knock?

[Wheelie]

Piston wear, they don't shrink.

[gpd005]

Well, i'm guess i'm not sure what spark knock is. It just started out of no where. I was racing at Lorretta's and it just started making this noise. I really just thought it was the valves but that's not it. i ordered a gasket set so i'm gonna try that now. We'll see how it works out.

[DieselBoy]

Yes, a piston can shrink. it can also wear. generally it's wear, though as most pistons now are heat treated

[exrider008]

Originally posted by gpd005
I've adjusted my valves and i yes i do have a web cam in it?

aftermarket cams have a tick to them did it start when u put the cam in?

[400exredrider]

are your rockers alright? springs and retainers in good shape? did you ever check for an exhaust leak?