gears not engaging

Hi people,

right, so today i decided that i'd strip out the clutch assembly as the bike was lunging forward and stalling when selecting 1st gear. soaked my plates in oil for a while, re-assmebled correctly and thought that would be grand.

No such luck.

Now, for a reason i can not fathom, the gear box will select 1st, 2nd 3rd etc, but when releasing the clutch not a thing happens.

anyone got any ideas? i'm sick as a f***ing chip!

cheers

[yorkie_chris]

Clutch adjustment wrong or reassembled incorrectly.

[muzikill]

can you change the gears without pulling in the clutch lever by chance? this would indicate the basket is extended and stuck open making the plates loose allowing you to change gear. i would expect the gear lever to feel very loose when easing it off if this is the case in fact it would have no spring to allow it to return.

[yorkie_chris]

You can always change without pulling clutch.

You removed the basket?

had a tinker on, and you know the little screw inside the nut at the gear change lever that adjusts the clutch rods, i have screwed it out and it works like a dream, so happy days.

next challenge, r6 throttle tube and the clutch safety switch, yahoo!!

[muzikill]

Originally Posted by finchy001

had a tinker on, and you know the little screw inside the nut at the gear change lever that adjusts the clutch rods, i have screwed it out and it works like a dream, so happy days.

next challenge, r6 throttle tube and the clutch safety switch, yahoo!!

I've realised as far as the clutch faults are conerned i will always be looking for something that doesnt exist. I didnt realise just how little the clutch basket moves out to do the job its made for.

Btw, id like a idiots guide into what that little nut and bolt actually does!

[Sid Squid]

Originally Posted by muzikill

An idiots guide into what that little nut and bolt actually does!

Remove the oil filler cap and look in, you're looking the clutch pressure plate, the pressure plate clamps the friction and plain plates of the clutch together to transmit drive from the engine to the gearbox under pressure from the clutch springs. It's the force applied by the springs that you are overcoming when you pull the lever to interrupt the drive.
Pull the clutch lever, you will see the pressure plate move away from the clutch plates, and return to them as you release it. As you can see the pressure plate moves only a few millimetres between lever fully out and fully back against the handlebar.
As you will have noticed the clutch cable pulls upon an arm and in doing so turns it, the lifter is a coarse screw which moves back and forth when turned, (think of how a threaded item when turned round moves along its axis), the lifter pushes a rod that passes through the gearbox and presses via a bearing onto the pressure plate, (the clutch is spinning around at a proportion of engine speed, without a bearing the rate of wear would be quite high), this is the push that is required to lift the pressure plate away from the clutch plates and interrupt the drive from engine to gearbox.
The lifter has a range in which it can turn to best advantage, the ideal point being when the angle between the cable and the arm is 90°, as such the adjustments of the cable and lifter are arranged such that the best operation is possible. If the lifter presses onto the end of the rod when the arm is too far rotated either up or down, the cable will not be able to apply best leverage to the arm, the screw in the middle of the lifter is the part which presses on the end of the rod, and adjusting it in or out effectively alters the length of the rod such that the lifter can be in its best range of operation.
For a demonstration try this: Turn the lower cable adjuster downward so there's plenty of slack, loosen the lock nut and make sure the arm is at the bottom of its travel, turn the adjuster screw outwards, (anticlockwise), a turn or so, note how the arm doesn't do anything, (if it now does anything at all that is), until it is right at the top of its travel - the adjuster is now too far away from the rod to be able to press on it, the rod is in essence too short.
Do the opposite; turn the screw in, (clockwise), until it touches the rod and then a further half a turn or so, no matter what you do with the arm the lifter is too close to the rod and can't back off far enough to allow the pressure plate to press fully on to the clutch plates; the rod is in essence too long.
Why is this needed - why can't the bits be made such that they're the right size?
As the clutch wears the plates become thinner, as they do so the pressure plate moves ever-so-slightly to the left - a bit closer to the lifter, from this it should be clear that that, and wear in the other parts of the clutch and withdrawal mechanism, will alter the necessary range in which the lifter needs to operate in order to translate its turning around into the small bit of push sideways needed to lift the pressure plate a few millimetres.

If I've explained it clearly that is.

[muzikill]

Pretty darn good i must say, it's a cracking explanation.

It took me (being a first timer) a while to get my head round how a clutch works in between the transmission and the gears!. Maybe this should be posted as a seperate thread squid, with a good topic heading and a pic to make it easier to search for in the future when people need this advice if they have issues with this important part on the bike.

If you post it i will back it up with a pic.

having more issues now, the clutch works when i first get going, but, after a mile or 2 it goes completely loose and gears become difficult to engage/disengage...really stumped now.

any ideas squid? you seem to be a fountain of knowledge