Noises from the motor?

[katrider]

I looked at a very nice '93 CBR900RR this past weekend. It looked showroom new, no lie. It has 20K on the odo, new tires, brakes, etc. From the looks of the bike it has had meticulous care over the years and the owner promises oil every 3K and other maintenance done on the clock.

So here's the rub: he started it while on the pit stands and it started right up, but when I blipped the throttle there was an abrupt and harsh sound, only for a split second, coming from down in the motor near the tranny area. Could feel it in the saddle a bit too, you know, that sensation that associates itself with the noise you just heard.

The bike never faulted, RPMs just snapped right up and it idled smooth and steady. More: he is selling the bike because he never rides it (replaced by a KTM SuperEnduro). Wondering if this bike suffers issues with the chain tensioner, or could it be the chain tensioner is sticking in it's adjustment 'cause it sits so long????

[Rogue]

I was going to say, chain tensioner.  They tend to have that tinny, harsh valve noise, especially when it is cold.

[Mac]

My f4i would do the same thing. It was a worn cam chain tensioner.

[katrider]

OK...I thought so. My 600 Katana was just starting to make some chain tensioner noise (they are famous for it...) when I gave it to my son-in-law (who is still riding the wheels off it 20K later!!!), and it had a similar harsh mechanical sound...

So, how difficult are they to repair on the CBR???

[Rogue]

 I have never done it.  Although I've seen mechanics do it on my Suzuki.  It looked pretty invasive although they didn't have to drop the motor.

Post it in Mods and Maintenance and see what people say.  I know a few have replaced their cam chain tensionsers on their Hondas.

[TuffguyF4i]

CBRs are noisey off the throttle if the idle is set too low. They give a grunty clunky sounds when revved off a low idle.

[tomek]

It is very easy job.New tensioner comes with locking tool that keeps the rod pushed in.Remove the old tensioner,( 2 bolts) install new one,remove the above  mentioned tool,you`ll hear "click",install small screw that comes with tensioner kit,by looking at old tensioner you`ll figure out where it goes.Or maybe you gotta pull that screw from the old one,I`m not sure,I have APE manual tesioner.If you have to pull it from the old one do it while the tensioner is still in the engine block,much easier this way.

After you are done it is good idea to put bike into 6th gear and rotate engine couple of times,just to make sure the rod in tensioner is extended before starting the motor.It is probably overkill thought,,,,,,,,..

It is 5-15 minutes job,in many cases ( cbr1100xx) you don`t even have to remove side fairing.

[GriffbsXX]

Changed one on the '99 bird, hardest part was pulling the fairing. Second hardest part was riding with "marbles" in the engine for a week waiting on the new and improved CCT to arrive.