Gearchanging problem

For some reason I cant seem to change down gear properly. The gear lever doesn't seem to engage lower gears. I'll change down into 5th, say, but then the lever becomes spongy and won't go into fourth. It only seems to happen when using the brakes though - if I use engine braking only it will shift down the gears. At first it started only happening from 2nd to 1st about a week ago, but now it's happening in the higher gears too.

Another problem now occuring is the engine losing power. Only occasionally, but for a couple of seconds it will almost die. It feels like it's run out of petrol - no engine braking occurs. It also splutters on occasion. I have a feeling it might be the air filter, as it's coming to the end of it's life (1000 miles left before scheduled replacment) and I also took the baffle out of the exhaust yesterday, which is when this problem began.

Any thoughts?

I reckon your lack of power is due to removing the baffle as the carbs may want rejetting with an aftermarket can, not normally, but it happens.

As for the gearchange, make sure the oil is not overfilled as this makes the gearchange difficult, if it is due a service in a 1000 miles it might be worth doing it now as fresh oil and filter could solve the gearbox problem.

I shouldnt worry so much about the air filter, just take it out and tap it gently to loosen the crap, unless it is full of oil, then it will need replacing

Fuzz....I Have you got a paddock stand? Try running the bike on that and go up and down the gearbox to see if the problem still exists? Is the chain correctly adjusted or does it have a tight spot?
Something and nothing going on here but needs checking out. It would aooear that your fuel/air mix is all messed up at the moment and new filter plus possible adjustments might be required.

[Sid Squid]

The lever pivot is most likely a bit gungey and stiff, this prevents the lever returning smoothly and thus the change mechanism cannot reset itself ready to change the next time.

First check that by squirting WD40 or similar around the pivot, if that helps, then remove the lever and clean and grease everything properly.

also check the chain tension...

Well I changed the engine oil completely, and also cleaned the gunk from around the gearchange shaft but the problem remains. I find it odd that it only happens if each gear is not put under load for a short time. This is fine during normal riding, but if I need to stop quickly I can't change down quick enough to get it into first before I stop. I can, however, rev the engine and let the clutch out while holding the bike back at the lights/crossing etc. and go through the box that way.

I'm going through the diagrams in the manual to try and understand how the gearchange mechanism works. From what I can gather, when the shaft turns, the pawls on the selector arm turn the cam plate, and then the spring on the selector arm sets it back into position. The stopper arm locates into the cam plate to make sure the gear is engaged properly.

If this is correct, could it be that the centralising spring is weakend, and therefore not returning the selector arm back to it's starting position straight away? Or, is it possible that the stopper arm spring is worn and the cam plate is not locating properly, so the selector arm can't find the pins as they are not in the right place, until the gearbox is under load?

To correct the spongy gear selector you will need to strip the brake pedal down, clean out the cr@p from around the bushes and re-grease. It is unlikely to be in the gearbox the problem will be in the pedal and bushes. When I owned my K3 this was a regular occurence during winter months.
To make the job simpler remember to secure the lock nuts on the gear rod, it is much easier than using a torch to find all the bits that fall off about 20 minutes after you set off!

This site never ceases to amaze me!

Coming in to work this morning and there's something wrong with the bike. Gears go up, gears come down... until you reach second. Then the movement is very spongy and just doesn't want to give the reassuring click into first.

This worried me and spent the next 10 miles trying every possible brake/rev/speed/clutch combination possible. Managed to find 1st a couple times but still a major worry. Fuzz, did you have any trouble finding neutral before this happened. I did, and assumed it was overfilled oil as it seemed to sort itself out and get a bit better. Wondering now whether this is a progression from that problem.

Luckily pulling off in 2nd is not too bad. Not looking forward to the ride home though. May need to train it for the rest of the week as well. Scheduling maintenance during the week is not likely.

Oh, back to the first line.... Started looking around for any relevant info... just about to do a search when this post catches my eye... fantastic.

P.S Happy New Year - the only good thing about being back at work is having the time to browse this site...

It's working again

Regreased the lever pivot and readjusted the lever height. I think the height played the important role, although I still haven't deduced why, but the lever does move more freely now.

Thanks for the replies

Originally Posted by Mariner

To correct the spongy gear selector you will need to strip the brake pedal down,

Really? How bizarre!