Hi all,
I'm riding a CBR600 f4i sport, a 2002 model for a week now.
Bike had done a little bit less than 7k miles.

Today when I was cruising on 4th or 5th gear (I'm not familiar much with the bike yet, and I am not 100% sure which gear was that) with about 40mph speed, I accelerated and went to about 5-6k rpm to overtake a car.
What happened next, was a terrible grating noise coming from around my gearbox, lost my speed and rpms while the bike jerked. It sounded like my chain or transmission grate and grind, it was that kind of a noise when a car's gearbox is half engaged in a gear. The sound was coming from around the gear lever area.

I clutched in at once, changed my gear down, and holding the clutch halfway in got on to the hard shoulder.
I stopped and examined the bike for any damage, there was nothing visible, no oil spills, no chain damage and the engine ran fine.
I slowly continued my ride home, as it was less than a mile. I had no problems whatsoever, transmission worked fine on all gears.

I thought I had a similar issue when accelerating hard once before, but there was no grind, and the bike picked up normally after a fraction of a second, so I just attributed it to my big clumsy foot messing accidentally with the gear lever.

Oil, all liquids and filters were changed right after I bought it, I had the bike examined by a mechanic when I was buying it, and he said it's a sweet ride, and all it needs is a set of new tires and most likely a cct changed within this year.. And now this

I do hope it's nothing real bad, I'm on a very tight budget at the moment

Did anyone happen to have an issue like that and could offer some advice?

Thanks!

 

For starters check your chain tension, a very loose chain can in theory do that. Also check the chain for any seized links. Check the condition of your front sprocket. It might be that the gear was not fully engaged but I'm not familiar with the f4i to be able to tell if that is common or even possible.

If it turns out to be the chain, do not, I repeat do NOT fall for the cheap 520 chains or some weird ebay brands, even on a budget. Keep at known brands, pinch the money from something else and save yourself from an engine overhaul due to snapping chain whiplashing your engine cover and cracking it. Besides, a good quality chain outruns two cheapo sets so in the long run it's not even more expensive.

 

I know this is an old thread, and I don't want to revive this. I was not able to reply to it due to some technical problems with the forums.
Just to close this down, the sound was caused by a bit of metal which got pulled in by my chain. I found it mangled and glued to some excess chain lube on my chain guard. It was a metal hook which came loose from a bit of elastic rope which the previous owner had strapped around the pillion.
It did no damage whatsoever apart from scaring the living daylights out of me