CBR600 F4 gearbox problem? Help!

[Rehab]

Hi helpful folks,

Was just prepping my bike for the Cannonball Run tomorrow and had finished cleaning the chain with it up on the centre stand. Popped it into gear to help fling off the cleaner before lubing it and something has gone HORRIBLY wrong. There is a noise in the gearbox similar to a stone flying around in there and it's catching so badly it nearly rocked the bike right off the stand. Obviously I won't be finished diagnosing and repairing the problem in time to do the Cannonball tomorrow so I have to pull out. Absolutely gutted.
Anyway, I was hoping someone could give me some helpful advice on the best way to diagnose the fault before I start pulling things to bits. I s'pose I could just trailer it to C'treads in the morning but I'm on a zero budget here so would at least like to know what the problem is before I start spending money. The wheel turns just fine by hand in neutral, so it aint a chain or rear wheel problem. Guess it's a pretty sure bet it's the gearbox, but can anyone suggest why this might have happened and what the likely issue is (about 85km on the bike)?
Only silver lining is I was riding earlier today and didn't notice anything at all, so I guess it could have suddenly jammed and spat me over the bars - at least I'm in one piece to try fixing the fucking thing. I have a workshop manual, the required skills if I work slowly and carefully, and I actually have a connection who has a 5000km gearbox if I need it.
Any brilliant advice??
Cheers and sorry if this is all stupid questions - bit braindead due to the massive disappointment.

PS If anyone wants a free entry into the Cannonball tomorrow let me know. You could use my pass and I haven't even put the numbers/stickers on the bike yet (luckily). Pick up from G'feild - cost ya some beer or sumfin - or just really good advice.

[tigertim20]

bit hard to tell without hearing it. a selector lost a prong off a fork, or a tooth lost off a cog maybe.
if you have the manual, do it yourself. take it apart slowly, take photos as you go to help you with reassembly.

[Rehab]

bit hard to tell without hearing it. a selector lost a prong off a fork, or a tooth lost off a cog maybe.
if you have the manual, do it yourself. take it apart slowly, take photos as you go to help you with reassembly.

Thanks for the speedy reply. Busy reading the manual now. Love the photo idea - wouldn't have thought of that so already worth asking on here! Thanks heaps

[Katman]

Bikes sometimes make weird shit noises when you idle them in gear on the centre stand all due to engine pulses plus transmission backlash plus chain freeplay.

If it rides ok there's more than likely nothing to worry about.

[tigertim20]

Bikes sometimes make weird shit noises when you idle them in gear on the centre stand all due to engine pulses plus transmission backlash plus chain freeplay.

If it rides ok there's more than likely nothing to worry about.

true, but if something has broken off inside, going for a ride on it would be about the worst advice ever . . .
the difficulty of diagnosing over the internet!!.

[Katman]

true, but if something has broken off inside, going for a ride on it would be about the worst advice ever . . .
the difficulty of diagnosing over the internet!!.

You appear to have just enough knowledge to be a danger to yourself........and yet, more than enough to make yourself sound stupid.

[hayd3n]

its a honda itl be sweet

[Rehab]

Bikes sometimes make weird shit noises when you idle them in gear on the centre stand all due to engine pulses plus transmission backlash plus chain freeplay.

If it rides ok there's more than likely nothing to worry about.

That'd be awesome news. However, does weird shit noises include something catching when in gear so much that it's goes rapidly tight then slack in the chain and rocking back and forth on the stand? Serious question in case it sounds like sarcasm. I really hope it's nothing to worry about and will wait for your reply before continuing (only have the fairing off at this stage).

Edit - Think I may have answered my own question - that's way too much noise to even try and ride and see if it's ok. It sounds really bad. If I were more pooter savvy I'd record it and put it on here, but I think that'd take longer than fixing it.

[hayd3n]

That'd be awesome news. However, does weird shit noises include something catching when in gear so much that it's goes rapidly tight then slack in the chain and rocking back and forth on the stand? Serious question in case it sounds like sarcasm. I really hope it's nothing to worry about and will wait for your reply before continuing (only have the fairing off at this stage).

Edit - Think I may have answered my own question - that's way too much noise to even try and ride and see if it's ok. It sounds really bad. If I were more pooter savvy I'd record it and put it on here, but I think that'd take longer than fixing it.

take a video and upload to youtube or facebook etc etc ,
maybe drain the oil and inspect it for foreign things

[Rehab]

take a video and upload to youtube or facebook etc etc ,
maybe drain the oil and inspect it for foreign things

Interesting. If you point a video at it and press record it reduces the noise significantly. I'm going for a quick ride....

[Katman]

Edit - Think I may have answered my own question - that's way too much noise to even try and ride and see if it's ok. It sounds really bad. If I were more pooter savvy I'd record it and put it on here, but I think that'd take longer than fixing it.

So it ran fine, then you put it on it's centre stand and it made some noises, and now you're too scared to ride it?

[Madness]

maybe drain the oil and inspect it for foreign things

+1. If I had a budget of $0.00 in your circumstances that'd be the first thing I'd do.

[Madness]

Interesting. If you point a video at it and press record it reduces the noise significantly. I'm going for a quick ride....

What are you smoking?

[bogan]

Noises are a really hard thing to convey over the internet!

I would suggest upping the idle significantly, say to 2,500, and seeing how that affects it, if it is driveline play I'd expect a fair bit of the snatchyness to go away, and just a touch of rear brake and it should all go away. If it gets worse in either case, maybe you got problems... GL

[hayd3n]

What are you smoking?

question is will he share it?

[Rehab]

So it ran fine, then you put it on it's centre stand and it made some noises, and now you're too scared to ride it?

What are you smoking?

Had a feeling I'd get advice and also a bit of a kicking from posting on here :facepalm:. Hence the attempted disclaimer in the original post about being brain-dead due to disappointment.

Anyway, at risk of taking another kick, I'll add that I noticed a funny knocking a few days ago just after startup heading down a driveway. It went away after a few seconds, or so I thought, and then thought I might have just been riding without my earplugs for a change and was just hypersensitive so I rode on. For the first time since owning the bike, which has been all of 6 weeks and 3000km, I either missed 3rd or it popped out about 5 minutes later. This added to my worry so I stopped and listened then rode on very slowly through all the gears several times and it seemed ok so I eventually continued and have since ridden about 300km on it. I have also corrected the chain tension so assumed that may have caused it.

I didn't want to dribble on about it in the original post, but that's why I was more concerned than I might otherwise have been when it was doing odd things on the stand. Weight was added by my neighbours looking over from their deck all concerned and saying it didn't sound good.

The bollocks about the video was meant to illustrate my bemusement/frustration that I couldn't reproduce the problem once I was in evidence gathering mode. Since the ride went fine, and I can't hear anything odd while I'm actually riding it, I'll whack the stickers on it and Cannonball tomorrow after all.

Thanks for the help.


And I can't smoke my pills, but I might take an extra one just to be safe.:doctor:

[p.dath]

Just having a think; at 85k on a CBR600F4 it would be due for a new cam chain.

Is the noise perhaps a rattling, like a chain rattling against the engine cover? Try going to You Tube and searching for it, and see if that is the sound you are hearing.
You'd also probably find that the sound will quieten down when the engine is under constant load (like Katman suggested) - if it is this problem.


And on another note; I know it sounds dumb; but had better check the obvious; have you checked that the bike has oil in it?

[p.dath]

Is this the sound you are hearing?
http://www.youtube.com/watch?v=1tqM_uHjKUA

[Icemaestro]

he said it was fine in neutral so won't be the cam chain...that will rattle away in neutral (got one right now doing it:-P)

[BASS-TREBLE]

How much slack is in your chain?

A bike in gear with the rear wheel off the ground and a loose chain makes some pretty screwed up noises since there is no load on the driveline.

Does it make the noise when in gear and the clutch pulled in?
I would sit on it as if you were going to take off and slowly let the clutch out, this would let you know for sure it its the gbox or loose chain/nothing to worry about.

[tigertim20]

You appear to have just enough knowledge to be a danger to yourself........and yet, more than enough to make yourself sound stupid.

feel the need to reply to illustrate your "I know everything" attitude again huh?

Pdath has a good point, now that you have mentioned it did it while cold the other day. Does that model have the same type of stock tensioner the F1 ans F2's did? if so they were well known for fucking out all the time, and the first sign of them dying is often a quick rattle when cold.

[Rehab]

Started to thank you all individually but ended up with a novel - so collective thanks.

Was definitely "weird shit noises [idling] in gear on the centre stand all due to engine pulses plus transmission backlash plus chain freeplay." Roughly 300km today and all is fine and obviously always was. Nothing like a paranoia attack eh?

Cam chain and tensioner recently done so that possibility hadn't entered the frame. Also, I sadly know that noise only too well.

Cheers fullas