I've been asking alot of questions lately, but this bike fell into my lap before I could do any semblance of research. I can hear my valves between 2.5k RPM's and 4k RPM's in every gear. After that the engine and exhaust overwhelm the sound. Now, it isn't super loud, it's sort of faint, but I can hear it when I am riding slowly in traffic. Kicker is, if I'm sitting next to the bike, and rev it slowly...I don't hear the valves at all.

Do you suppose they need servicing, or is it normal to be able to faintly hear them? I am running 5W40 Synthetic Rotella oil, new filter, and the oil light is not on. Oil is filled just a tad unfer the full line, and looks as clean as when I put it in.

 

That's a really good question, and one I'm not qualified to answer. However, I've never really heard any chatter on mine, but I haven't ridden without a helmet for quite awhile. I would try 10W40 and see if it goes away. Are you sure it's not just clackitty chain clack?

 

No, it's valves. I know what valves sound like, I owned a mid 90's Mazda MPV lol, infamous for valve noise. It's not loud at all, it could also just be the exhaust system amplifying the exhaust valves during WOT at those RPM's, but I do hear it. I dont think I heard it when I was using the 15w40, but everyone says the 5w40 should be fine to use.

 

Might it be the CCT gremlin acting up?

 

I never hear my valves, on cold startups though I do hear a "clunk" if I don't let the bike rev to about 2000 rpm when it's warming up.

How many miles on your bike and how many owners has it had?

If the valves have never been checked, it might be time.

And maybe check the CCT too, might be that and not the valves.

 

CCT = ?Timing chain?

It has 27,000 miles, He has some maintenance records. I am the 3rd owner of the bike. I need to rummage through the receipts to see if there was some servicing to the heads done. As far as actual valve checking, is it an easy process? I know getting to the top of the engine is relatively easy, but getting clearance tools in there could be annoying?

Thanks for all the help guys.

 

CCT is your Cam Chain Tensioner....if it doesn't work, your engine can be seriously damaged or so I've read.

Valve checking is pretty labor intensive, I think, but you can do a search on youtube.com and put in key words like "motorcycle valve adjustment" and see how it's done.

Not for beginners but we all gotta start somewhere -- I've never done it.

 

Technically it's the cam chain tensioner lifter. In the cbr the stock one is notorious for crapping out. A lot of people switch to a manual one. I'm dealing with a similar issue and trying to get myself up to throw my APE cctl in.

 

Well, I did valve clearance checking on my 1983 XT550, but that was 4 valves total to check. The CBR I believe has 4 valves a cylinder. I ran premium gas to triple check it wasn't detonation, but it remained.

I think I am going to order the CCT tensioner (manual one from APE) and a new thermostat and put them on all at the same time. I had a coolant leak today and the reservoir is low, and I think either the Output shaft(front sprocket) has a shot set of bearings, or the water pump is dying.It sounds like bearing noise though.

I had the bike put on a dyno today...Dynojet. It put 117.1 RWHP down, but the delivery wasn't as linear as I liked, it had a dead-ish spot between 4k-7k RPM's, then shot up and kept going til the rev limiter. I was happy with the results overall though, sometime this summer it will get a proper tune.

Unfortunately, on the ride home I heard a new noise coming from the left side. Sounds like an air leak at the box, but it is coming from the case, around the front sprocket area. Sounds kinda like squeaking when under load, but when just gliding in gear, it doesn't make any noise. I wish I could understand this bike haha.

 

How old is the chain. An old chain can make all sorts of strange noises.