Topic: Clutch issue ?

[muzzy]

Hi, I have recently got my CB750 K4 going after a long layoff, I now find when running it won't come out of first gear to neutral with engine running, its fine when I turn engine off it will return to neutral.
I haven't Ridden it with this issue so don't know if this would help, difficult if I can't get it out of first gear. In fact, I have never ridden bike after importing from USA some years ago
The bike has done 16,000 miles so would this be the life span of a clutch?
The slack/free board at the clutch housing operating cable is certainly not the recommended 3/4" It's more like half that.
I haven't had a go at adjusting it at the housing with the lock nut and screw where you tighten until drag then back off.
All comments appreciated.
Regards Murray

[jaytee-nz]

Sounds like you need to adjust the clutch in accordance with the manual.
If you don't have a Honda service manual, it would be a good idea to download one from this site.
Cheers - JT

[newday777]

Did you pull the clutch plates out and inspect them? They may be stuck together and need to be cleaned up from setting. They get gummy and rusty plates from old oil left in the motor over many years. At 16,000 miles the clutch shouldn't be worn out. Beadblast/vaporhone the steel plates and clean the clutch discs, then lightly sand them to refresh them(keep in order and direction when you pull them out)

Yes a proper adjustment at the actuator lever nut behind the clutch chrome decorative plate is necessary per the service manual, then at the clutch lever.

The other thing to check after you make sure that the discs and plates are not gummed together is behind the transmission cover (left side, that has the shift shaft rearward of the alternator cover, you will need a new cover gasket to do this), the large Allenhead screw holding the shifter hook might be loose. When Sean(The Lone Builder/Belfast to Belfast/2) stayed at my place back in May this year, he had a problem of his K2 from Ireland that he bought new not shifting to neutral that adjustments and checking the clutch pack didn't correct. Talking with HondaMan, he mentioned having found the large screw loose on more than one bike he had repaired.

Report back what you find here.

[rotortiller]

Mine gets stiff from time to time while finding neutral. Depends on the temperature and how long the oil has been in service or oil type. Select neutral while the bike is still rolling to a stop, that works for me when it occurs. It can be a clutch issue or not. Old clunky CB xmission is not like a modern bike. Just ride the sucker for a bit and likely it will get better when the clutch plates clean themselves off. Should work the same as when you put it away after a good ride.

[muzzy]

Thanks, will look at the adjustment first, At the clutch housing the cable operating the lever what amount of free play in the cable should there be?

[HondaMan]

Thanks, will look at the adjustment first, At the clutch housing the cable operating the lever what amount of free play in the cable should there be?

First adjust all the slack out at the clutch lever, then go down to the clutch cable where it enters the engine and make sure the adjusted length of those cable adjusters leaves a little bit of slack (1/4"-1/3" at the clutch lever). Then loosen the nut on the clutch's lifter arm and turn the screw in the center until it takes out all of the slack. Then turn it the other way a partial turn so there is no more than 3/4" clutch lever travel, 1/2" is usually better. This will change again after you've ridden the bike some to refresh the clutch's cork plates with oil.

On the oil topic...if you are using a high-detergent car oil instead of a low-detergent type, the clutch will likely slip some while it is resettling. The corks get too slippery with that detergent in them, so it takes a hundred miles or so for things to settle down. Then you'll have to repeat this adjustment.

After the clutch works again, change the oil and the filter: there will be some fine grits of the cork plates in the filter. I'd advise using a correct oil then, like the Bel-Ray 20w50 EXL Mineral or similar, NOT car oil with detergents. They foam in this engine at high engine speeds, causing low oil pressures and clutch problems.

[muzzy]

Thanks very much, makes sense I will also Change oil to a 20/50 mineral based.
Can always count on the forum for good solid assistance.
PS hondaman I was the guy bugging you re spark tool I did manage to get a genuine Honda part to finish my tool kit.
Regards Murray

[scottly]

Thanks, will look at the adjustment first, At the clutch housing the cable operating the lever what amount of free play in the cable should there be?

Do the adjustment of the screw at the clutch cover first, with slack in the cable. I set it be how much I can move the lever with my finger: about 2-3mm. Once that is set, adjust the cable until you get a minimum of free-play at the end of the hand lever.

[muzzy]

Thanks, Scottly,
just the sort of hands-on information I'm looking for.

[HondaMan]

Thanks very much, makes sense I will also Change oil to a 20/50 mineral based.
Can always count on the forum for good solid assistance.
PS hondaman I was the guy bugging you re spark tool I did manage to get a genuine Honda part to finish my tool kit.
Regards Murray

Did you ever find one? I still haven't. I have 2 CB750 bikes and toolkits to reassemble soon. The local bike junkyard offerings are pretty slim: it looks like he did a massive scrap operation last year and there's nothing older than 2000 there now.

[muzzy]

Yes I did, local bike wrecker/junk yard