Whats up guys new member here i have a question about my cbr600 f2 its a 91
After it warms up and i shut it off , then start it back up i get a terrible engine noise.... I cant see it being the cam chain and i doubt its an exhaust leak. It does not change with clutch in or out nor in gear or neutral.
Any ideas? It is a high mielage bike having 57k on it but it runs damn good. Im stumped. Any ideas are greatly appreciated

 

Terrible noise, like marbles in a coffee can? Shut it off warm, then start it up and it makes noise. I'm almost sure it's the cam chain.
If it's making the noise and you raise the rpm up slow, does it go away?
You have the stock tensioner on the bike??
If you do, go get an ape tensioner and put it on. Even if this isn't cam chain noise right now, you'll get it eventually.

This made me laugh.

 

Haha glad you like that , and yea im an auto tech so by knock i mean sounds like catastrophic failure not just valve chatter. However the noise is more present in the top end. As far as rpms wise it does get slightly louder until the point the exhaust drowns it out, but does not go away with rpm rise. Bile feels strong she still pulls hard and by the exhaust note it sounds likes it running great. Daignosing a knock is usually easy lol
And im going to order the tensioner asap thanks

 

Yeah, when the tensioner gets old, it will let the chain get loose. The loose chain will rattle. Eventually it gets worse and starts to slap against the upper chain guide, which is metal with a plastic slide. After a lot of slapping, the plastic slide can break off. Then you get cam chain banging on metal. Only problem is that I don't think the upper guides are still available from honda, so it may be worth a check if you are thinking of adjusting the valves.

A manual tensioner is a must do on F2's with any kind of mileage. I'm still 90% sure that is your problem.

But more info never hurts, so Did you just buy the bike? Did you just work on it? When did this noise start?

 

Yea i just bought the bike less than a week ago. I notoced the noise 2 days ago and then today as well. But today i nade the bike mimic the noise so i could try and pin point it. I have not worked on it yet. I pad 600 bucks for the bike so if it blows up im not going to lose sleep over it lol. F2 engines seem to be pretty cheap and id probably just swap in a f3 motor at that point. But as far as the cct being the culprit i will know soon enough, but you think a cct would cause an internittent issue like that? And wouldnt it make more noise cold than hot?

 

No, they tend to be quiet when cold because the oil is thick and builds more pressure. Once it warms up, the oil gets thin and oil pressure is less at idle, they will rattle.
Usually if you rev them up a little to build a bit more oil pressure, it will go away. Sometimes they will also rattle after high rpms. Then tensioner uses oil pressure and a spring. It can also get clogged if the oil isn't changed regularly.
Symptons aren't always exactly the same and it depends on how bad it's gotten. But damn near every F2 I've ever seen that made noise, it was the tensioner.

Here's the guides out of my high mileage bike when I replaced them.

 

Oh ok that makes more sense and wow id say they were a little worn lol. Well i guess until i get that ape manual tensioner i wont know for sure but i do appreciate the help. Ill be ordering that soon and ill update then. Hopefully she lasts in the meantime lol

 

I got my bike for free. With a clear title no less !

I've worked on Japanese OHC engines for a long time. Any really bad noise I've had was was due to the cam chain and tensioners.

Not sure if I have an aftermarket tensioner or not. I do know that the more I work on this bike, the more I like it.