Cam chain screeching

[Whiplash]

Hi All,

I replaced the cam chain on my 2000 'busa about a year ago and it began making a high-pitched, very loud, screeching noise above 4500 RPM...below that, no noise at all. It doesn't increase in decibels and likewise doesn't go away at higher RPMs. It's like flipping a switch...it appears at about 4500 and stays there until the RPMs drop below that. It makes the sound when idling or under load. It runs fine but it's embarrassing to drive so I parked it until now, and now that it's summer I want to get it rolling again. It sounds like it's coming from the top of the motor on the cam chain side. Do you think the top cam chain guide might be bad? Not sure if a bad guide would cause that type of sound, but it didn't make the sound prior to replacement.
I replaced it because the old chain was too loose. The tensioner was at full extension and the chain was making a rattling noise, but nothing as loud as the screech it's making now. I got the new chain from Competition Cams so it should be a quality product. Tensioner is hydraulic.

 

[greg3852]

I have broken two cam chain guides. Pop the top and look before you do some damage.

 

[greg3852]

 

[Whiplash]

I removed the valve cover after I first heard the noise. I thought I might have screwed something up after replacing the chain. Everything looked fine. I checked the cam timing marks and even reseated the top guide, but the problem persists. I've only driven it around the block a couple times since the problem started so no worries about additional damage.

 

[LC4CARL]

I'm trying to associate a screech noice with the cam chain itself and failing. The rattling I get. What is involved with changing the chain on one of these? It there something on these bikes that comes into play at 4,500 plus?

 

[greg3852]

How about posting a video of the noise so we can hear it? Post it on youtube then you can link it here.

 

[Whiplash]

The battery has died from sitting so long without running and won't hold a charge. I've got a new one on order. It's supposed to arrive tomorrow. I'll fire it up over the weekend - assuming there's no other issues after sitting so long - and make a video of the problem.

 

[Whiplash]

I'm trying to associate a screech noice with the cam chain itself and failing. The rattling I get. What is involved with changing the chain on one of these? It there something on these bikes that comes into play at 4,500 plus?

I don't know why it would be making the noise either but it wasn't present before the cam chain swap, so I'm going with something related to that as the cause.

 

[Whiplash]

My memory was faulty…it definitely is more of a loud rattle than a screech. When I pulled the valve cover to check it before I also removed/reseated the tensioner but it still made the noise. I’m now wondering if the tensioner isn’t extending to take up the slack. I’ve attached a link to the video.

Busa rattle

 

[greg3852]

First place I would begin is that tensioner. Sounds like it isn't doing anything or is tight af

 

[Whiplash]

Cool, I'll check it out again...probably next weekend. With such a loud noise I'm going to assume it's not extending enough and the chain has too much slack.

 

[Whiplash]

Looks like the problem is I have the wrong model tensioner. The shop manual shows a non-hydraulic but mine is hydraulic. I bought the bike new and have never replaced the tensioner so not sure how I ended up with the newer model, or how it was working for 20 years without issue. It’s too long so it’s applying too much pressure against the chain guide. You can see the chain was cutting into the guide and I’m assuming, causing the noise. I looked at part numbers all the way back to ‘99 and all the busas have the same cam chain so I don’t know how the tensioner wasn’t always too tight. It seems like the chain needs a couple extra links. I think my only option at this point is to order a manual tensioner. Even when the tensioner is fully retracted, it’s already pushing too strongly against the guide.