Stretched timing chain?

[Bartman]

I have an auto tensioner, but when I crank up after sitting over night or after work, I hear what sounds like the timing chain slapping in the front of the motor.
Once it warms up I don't hear it any more.
I wonder if the auto tensioner is maxed out and my chain is stretched?

I guess I could put my old manual tensioner in to see if the noise stops, but it doesn't leak a drop now and I don't want to fool with it if not truly needed.

The motor has a little over 38k miles.

Any thoughts?

[BA80]

Video with audio????

[trbig]

Hmmm.. A warm chain would become even more loose. I have heard of the teflon pads coming off the chain guards, but I would think it would make the noise all the time.

Have you checked your earl lately? (Oil to you non-southern folk..) and when was the last time you replaced the filter? Have you recently put a windshield or fairing on? The new noises coming from the motor after I did that the first time scared the heebie jeebies outta me.

[tcoop]

I'm having the same issue with the 78E that I just put back on the road. It has fresh oil and a new filter. I am going to check the auto tensioner to see if for some reason it is not ratcheting properly. I know it has not maxed out. The only other thing I can think of is oil is not flowing properly, (the engine did sit for a long time) clogged oil pump screen or poor oil pressure.
The auto tensioners on the 80, 81 and the XJ are all working fine.

I will take a video of what mine is doing in the morning so we can compare.

[TomB]

Piston slap sounds like that too, and from the same area, once warm the noise stops.

The good thing about the manual CCT is you can tension up the chain then remove the CCT and check how much travel is used up on the spring loaded rod.

[jetmechmarty]

If the teflon, (or whatever it is) departs the chain damper assembly, I would expect you'd be finding pieces of it in the oil filter. That stuff has to be on the damper or in the filter. You would be finding little black strips of plastic.

[bikerphil]

I hear what sounds like the timing chain slapping in the front of the motor

Could be the HyVo chain slapping around in there (common occurrence) and when the motor is warmed up and running smoothly, no more slap. Sometimes syncing the carbs will quiet it down, YMMV

[tcoop]

This is when it is cold

http://s850.photobucket.com/user/tcoop_album/media/Bikes/VID_20140918_075105_183_zpsheu8j7oi.mp4.html?sort=3&o=0

This is when it is warm

http://s850.photobucket.com/user/tcoop_album/media/Bikes/VID_20140918_080746_231_zps06zb0iy2.mp4.html?sort=3&o=1

I had to download the video to se it hopefully it works.

[bikerphil]

Definitely sounds like valve train noise. You can check for too much chain slack by removing the valve cover and pulling upward on the chain at the bridge, shouldn't have any more than 1/4" of travel.

[trbig]

Doesn't sound like the cam chain to me. Almost sounds like pre-detonation, but in that area, you might take off your sidecover there and take a look at your timing assembly and make sure it's not flopping back and forth, or that it isn't rusted and moves freely. Also check for vacuum leaks in the rubber line going to it.

The engine sounds a bit lopey to me like it could use a good carb synch, but I could also just be hearing that exhaust closest to the camera.

[BA80]

The older engines will lope a little because of the cams when they are cold or idling too slow.

You could be onto something with the vacuum advance though Tod. We started the MNS Doc just got the other day just after he got all the parts swapped over from his SG and it sounded like it had a rod knocking. After looking it over and noticing the vacuum advance hose had been hooked to the boot rather than the #2 carb I switched it and the knock went away.

I was also thinking maybe an exhaust leak on Bart's bike too. They seem to go away when the engine and exhaust get warmed up too.

[BA80]

OOPS! I mean tcoops bike.

[Bartman]

It is getting close to oil and filter changing time but don't think that is it. I had to take the exhaust off last weekend to put the new tire on and that seems solid.

I will try and get an audio of it this Sat. Morning...

It is not constant, just a little random slap inside front while idling at cold warm up.

I am going to try and come to N.C. Next weekend for a few hours, but it won't be cold for anyone to hear then.

[BA80]

You should try and come to NC and at least stay for one night. Your not that far away.

bikerphil, I, and many others who could be of help will be there. Friday evening would be best.

[bikerphil]

Might also be a broken internal pipe in the factory header, might try tapping on them with a rubber mallet.