Hello.

So, i just got a CBR 600 F2 (1992)

The bike compared to my previous bike (zzr 600 1992) Is running incredibly smooth and just passed 60.000 km (37.200 miles)
Well that was up until a couple days ago. I took it for a ride and put some pressure on it through 2, 3 and 4th gear. At the end 4th gear i prepared to shift but it jumped out into a fake neutral and started to rattle really bad and loud.

I tried to pull the clutch and shift up into 4th again but it just made a rattle noise and did not want to go up. I tried to shift down and it allowed to go down into 3rd.
Still really loud rattle from the engine.
Got picked up and later got it to my garage.

Wanted to let a friend hear the rattle and fired it up a couple days later and now the bike sounds just as before? No rattle or anything.
Shifts into all the gears no problem and clutch also engages fine.

drained the oil and opened the clutch cover to look for damaged parts but absolutely nothing!?? The oil looked brand new and zero debries of any kind in it.
I read about the CCT is hydraulic on these bikes and also found out that it can fail in high rpm and when the throttle is shut, causing the cam chain to become lose and possibly go out of timing...

I was "quick shifting" the day it happened and I now believe that the CCT is the reason it made that loud rattle.
So i was wondering if anyone have had the same issue or can tell if im correct in thinking that the CCT is the culprit?

Thanks for reading.

 

I agree with your thinking.

If you miss a shift or the trans pops out of gear. The trans can make some bad grinding/crashing noises.
Those are a deep grinding bang type of sound. Once you get it back into gear, the noise will stop.
If you let the rpms drop to idle, it hard to get into gear and it will usually grind when trying.
It's helps to keep the rpms up when trying to get it back into gear - rev match, then it will go back in easier.

Cam chains make a louder top of engine rattle. Sounds like marbles in a coffee can. Very tinny sound.
Cam chains can rattle at idle during cold startup. They can also rattle when warm after chopping the throttle after high rpms.
Usually not serious, it's just an annoying noise, it doesn't cause any damage unless you let it go for a LONG time like that.
It usually drives most people crazy before that. Putting in a manual CCT is cheap and easy and a permanent fix.

So what I think happened, is the bike didn't go all the way into 4th.
When you got to higher rpms, it popped out, causing the bike to rev even higher.
This mostly like causes the CCT to stick and start rattling.
Later you after the bike cooled and the oil thickened, you start it and the noise is gone.
At least for a little bit - it will be back...just like the Terminator!

 

Hi Phil.
Thank you for your thoughts.

I am just now going to have a look at the cct and hopefully will be riding later today.

Will update if this is the fix or i have to take a look at the top end as well.