Timing chain clack?

178 Views 4 Replies 2 Participants Last post by SCJ, 10 d ago

SCJ

Discussion Starter · 10 d ago

Just bought a very nice 1980 LTD 1000. When you start it cold it has a pretty pronounced "Clack" not tick that intermediately sounds off. Its not cam follower
noise, they all check good and is not making the noise in rhythm with the idle speed just every couple of seconds but its loud. At first I though it was
backfiring through the carbs because they have individual filter pods and you can hear them over a enclosed filter system. It runs fantastic
and goes away when it gets warm. Mine has the auto chain tensioner that has one single bolt on the side. It moves in automatically to keep the
slack out of the chain. I'm guessing its a chain slap but can I get some opinions. 27,000 miles but well taken care of. Thanks

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Kawasakian

· #2 · 10 d ago

Maybe run some "Sea-Foam" in the oil to clean up anything that may be clogging the automatic tensioner. Cam Chain problems, especially when cold could cause a cam chain jump, and that leads to catastrophic failure. Most of those units unbolt from the engine and can be checked. You would have to own the factory manual to know this. That's not a lot of miles on a big bore bike. If it goes away when the bike is warm, don't take off with it cold. Sea-Foam works wonders, use only the amount recommended. If it's possible to remove the tensioner, and it just costs a gasket re remount it, might be worth it. A lot of vehicles make strange noises when they start, and frankly, if it goes away, maybe why bother.

I have a lot of experience of Mercedes Benz V-8 engines. When they clack when cold. you shut off the motor and immediately change the tensioners, as they are "gunked up" and one day soon, it starts, jumps the cam chain, and bends all the valves. Speaking from experience here. I let someone else adjust the valves once after back surgery, and he broke the oil tube the feeds the cam towers, which seized the overhead cam chain, and I lost the motor, it was a 1975 450SLC. Can't go into what happened afterwards, but he suffered for that error. Point is, only you know your bike, and the sounds tht may just be parts of it's waking up process.

You have to decide how hard to go into it. Get the "Factory Manual", it is a must for a bike you intend to keep.

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SCJ

Discussion Starter · #3 · 10 d ago

Kawasakian said:
Maybe run some "Sea-Foam" in the oil to clean up anything that may be clogging the automatic tensioner. Cam Chain problems, especially when cold could cause a cam chain jump, and that leads to catastrophic failure. Most of those units unbolt from the engine and can be checked. You would have to own the factory manual to know this. That's not a lot of miles on a big bore bike. If it goes away when the bike is warm, don't take off with it cold. Sea-Foam works wonders, use only the amount recommended. If it's possible to remove the tensioner, and it just costs a gasket re remount it, might be worth it. A lot of vehicles make strange noises when they start, and frankly, if it goes away, maybe why bother.

I have a lot of experience of Mercedes Benz V-8 engines. When they clack when cold. you shut off the motor and immediately change the tensioners, as they are "gunked up" and one day soon, it starts, jumps the cam chain, and bends all the valves. Speaking from experience here. I let someone else adjust the valves once after back surgery, and he broke the oil tube the feeds the cam towers, which seized the overhead cam chain, and I lost the motor, it was a 1975 450SLC. Can't go into what happened afterwards, but he suffered for that error. Point is, only you know your bike, and the sounds tht may just be parts of it's waking up process.

You have to decide how hard to go into it. Get the "Factory Manual", it is a must for a bike you intend to keep.

Thanks, I do have the shop manual and build auto engines as a hobby. The noise does not have a rhythm to it like a steady "clack", its every few seconds which more points to
something loose. My tensioner is the auto type but I just bought a new one, since for 30 bucks why not go new. I will post what I find. Remember that you are standing a foot away from an open engine made of aluminum which amplifies noise considerably. I will change the tensioner and if no help will pull the cam covers and check the cam slack. I think between cams the chain should have a deflection of 1/8 to 1/4 of an inch. Sound about right? Appreciate the help.

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