engine knock

But how can it be?? The threaded internals of my tensioners are smooth and functioning as they should. What causes the knock actually? I fail to see how a cam chain or any of it's components could cause a knock like this. Do these stock tensioners not hold tension as tightly as they should or what?

 

The ccts can cause a rattle more than a knock, tension is held on a threaded plunger by a wound spring, which can break and cause the plunger to back off allowing the cam chain to rattle against the internals, but other than that, the cct itself can rattle itself while the spring is still intact, due to just the looseness of its own mechanism, and this case isnt serious because the tensioner is still doing its job.
If the spring is broken, (which is easy to check) the cct should be replaced ASAP as engine failure can result if the cam chain jumps teeth.
I dont think the noise you are hearing is cct related, as a cct rattle is worse when the engine is hot, and you said yours is only when cold, which makes me think its a lubrication issue. but as you say, just ride it and it will either get worse in which case you can do something, or it will dissappear itself.
As I said, I had a similar thing when I used a 5w40 full synthetic and it went when I went back to a 10w40 semi synthetic.
My knock was like a pre-ignition knock,or piston slap, and when I increased the idle speed to about 1400 it went away.

 

OK, this is interesting.
I called a dealer today, inquiring about replacement tensioners. He gives me a price, tells me he can order them, and then tells me that there are two numbers listed, an old and a new replacement number. He says the part number change indicates that Honda superceded the part so it's different than what the bike was built with. Essentially it's a re-designed part he says. That's fine, I know that happens.
Then I called another dealer. He said the first dealer is full of crap, and that no superceded part number exists. This confused me because the first parts guy gave me both the numbers, old and new. He also quoted me $97 a piece for the tensioners, while the 2nd place I called quoted me $69 a piece.
I'm surely confused now

 

Ask the dealer on what year models were the so called upgraded part fitted, and how to distinguish one from the other.
It is possible. On the VTR1000 which uses a similar tensioner, they were designated by a coloured dot on the body of the tensioner, IIRC pink was the older and orange was newer, or vice versa. They looked exactly the same, and I dont know what the difference was.

 

I wanna update this problem.
After hearing what some guys said on here, and finding out that Honda had a rash of cam chain tensioner problems on these bikes that I could verify, I purchased one cam chain tensioner. It's the re-designed Honda part with a new part number, which indicates right there that Honda is acknowledging a problem. So I bought just one, and replaced the tensioner in the front cylinder. And whattaya know....noise is virtually gone. I've been riding the bike every day for nearly a week now, and the loud and embarrassing knock it had is gone. There is a slight bit of noise still but I got the steth out and it's coming from the rear chain. I will change the rear tensioner at some point after our trip this weekend, and I'm comfortable saying that all my knocks and clacks and ticks will be totally gone.

 

I had a Syclone pickup for the better part of 20 years. It had a lot of noise at idle. It was injector noise. Very clattery.

My motorcycles are carbed and they work fine.

 

You think those injectors were loud, have a listen to GM's new "direct injection" setup. High pressure injectors that spray directly into the combustion chamber like a diesel, THEM fuckers are LOUD!!

 

kbee

i have a 95 vfr and also hear a come and go knock. bike has 53000 miles on
it and i have had it for 6 years . nothing adverse has happened. and doesnt
affect performance. i do have a question for anybody out there. the bike has
started to surge lately at a lower steady speeds esp around town. possibly
partial blockage in carbs due to ethanolitis? any thoughts? and can i help
the situation without removing carbs because it looks like a major pain to
r and r.

 

I have doubts to weather ethanol in the fuel would cause a blockage. The only way I could see that happening is if your carbs were allready gunky and the ethanol helped to break it loose. Ethanol tends to chew up rubbers and plastics that were not meant to deal with it, therefore not clogging things but potentially causing leaks. If you do suspect your carbs to be gunked up and clogged up there is no replacement for a good rebuild and re-synch. If it's not too bad you could try running some seafoam through it to see if it clears up a bit. Most likely what you're looking at is a re-synch of the carbs anyway, which you might try before dis-assembling anything to see if the problem clears up.