Hey Guys,
I recently purchased a 1999 CBR 600 F4. Here are the issues I am experiencing.
1. The bike seems to have a bit more vibration that I think is normal. The vibration is most apparent in neutral around 4500-5500. And during heavy acceleration in first and second gear.
2. I have been noticing a ticking noise that appears to be coming from the left side of the engine. It is heard most while downshifting.

Here is what I have done/checked already to the bike.
1. New oil and filter
2. New Spark Plugs
3. Carburetors Synchronized
4. Carburetors Cleaned
5. I also ran a bolt through the back of the Cam Chain Tensioner to see if the noise reduced. But no such luck.

Any suggestions would be greatly appreciated! Thanks!

 

Is this noise that you speak of going with the Rev of the engine right at start up? How many miles are on your bike? Generally if you get a ticking noise between 4-6k rpm it is the CCT. I don't believe putting a bolt down through your stock CCT will help but i may be wrong. If the ticking is constant with the revs or even when it is sitting still it may be your valves that need to be adjusted.

 

This noise does seem to be some what consistent with RPMs. However is not heard all of the time. It is heard the most while downshifting (engine braking). It also appears to be more obvious when the engine is hot. I am not leaning toward a CCT just yet for two reasons. One because tightening up the tensioner made no difference. And because it can be heard most on the left side of the engine. With or without a stethoscope. I leaned toward valve train when i first started looking at the issue, and saw no problems in this area. The bike has 35,000 on the clock. This noise doesn't appear to affect the performance at all. If I cannot find a resolution, I may throw a CCT on it to be sure, but I just thought I would see if anybody else has run into a similar problem. Any other suggestions or diagnostic strategies would be greatly appreciated.

As for the Bolt trick. This is a commonly used remedy for a sloppy CCT. It is not the correct way of fixing the problem, but is a good diagnostic tool. This method is done by removing the bolt in the back of the CCT and replacing it with longer bolt. You run the bolt in finger tight and lock it in place with a nut. This will minimize the piston fore and aft movement and hold the chain tight. Allot of guys do this as a "cheap fix". However, I simply tried it to see if there was any change in the noise. No such luck.

Any thoughts on the other issues I described?

 

What about a broken exhaust stud?

hrm - I'd need more to go on really... left side... hrm

 

I don't think this is an exhaust related issue. Definitely an engine noise.

 

well what did the #1 spark plug look like compared to the rest? If it is a fuel, spark or valve problem with #1 it should be visible on the plug.

 

Plugs are new. Old plugs looked fine. This is a noise that is not affecting performance as I stated before.

 

I'm guessing by that that you already have a manual CCT?

 

After owning the bike for a short period of time, I'm not sure how you know that it hasn't affected performance.

Noise comes from somewhere... that means the first things to think of are ignition related issues. After that you start to get into valves, cam chain tensioner, cams and crank. All of which would affect performance to some degree. All except the last 3 would show up in a plug reading. One valve out of adjustment would make some noise... and perhaps that's all it is.

If it doesn't' effect performance at all - then start looking at things not part of the motor - like a lose bolt or a rattling lever.

 

Ok. Well As I ALREADY stated, I've gone through the valves. It's not valve adjustment. It's not a CCT. I've never heard of a fuel issue causing a noise such as I'm describing, so I think you're shooting in the dark there. This is an engine noise. Could be valve guides, could be piston slap, I just wanted to know if anybody has had this issue before. Or any problems like this before.