HELP! Clutch not disengaging! CB400F

[zombie365]

Hi All,

Just come to the end of my CB400F cafe racer build. I’m having trouble with the clutch.

The clutch is not disengaging. The bike starts perfectly fine when in neutral.

If I try and start engine whilst in gear whilst pressing clutch lever, the bike jumps forward as if the clutch isn’t pressed.

When bike is in gear with engine OFF, I rock the bike backwards and forward the back wheel is engaged with engine, there is no difference if clutch is pressed or not.

Kickstart will not engage either, it springs back into position, but it won’t engage properly to turn the engine over. Only tried kickstart when in neutral. Maybe this is related?

The engine has been stood dry for the past year whilst building the bike.

I did remove and refit the internal kickstart mechanism as it fell out when I took engine case off for refurb.

I have adjusted clutch cable so that it reaches max leverage on clutch arm, therefore clutch should definitely be disengaged.

Any things I can try before I start disassembling?

Any help would be appriciated!

Cheers,

Sam

[Oddjob]

No, disassemble. You'll clearly fitted something wrong. Try and remove all the clutch plates and see if any are stuck together. Kick start is clearly not fitted right or it would work.

[TrickyMicky]

Cannot help re. the kickstart problem, but, when my bike was put back on the road after 9 years the clutch would definitely not free off. Rather than dismantle the clutch cover etc., I clamped the handlebar lever in the release position, removed the dipstick, then the clutch is visible. Very gently with a flat bladed screwdriver it is possible to carefully part each plate from its partner whilst turning the engine over a little at a time. Be luck, Mike.

[McCabe-Thiele (Ted)]

I agree with Ken you need to disassemble the side cover and check out the two mechanisms.

Did you seperate the clutch plates before you put it back together - they can as you probably know stick together easily when left standing?

The clutch has that odd plate holding the 3 balls, plunger etc might be an issue there somewhere with an incorrect spacer fitting.

The kickstart should be straight forward to check - the spring can be fidly.

[Nurse Julie]

Have you put #115 in the correct location, a lot of people don't.
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[zombie365]

Alright guys,

Thanks for the replys.

So dropped the oil and took cover off last night. I carfully and lightly used a flat bladed screwdriver to seperate plates whilst dripping engine oil in between plates. After I put cover back on and filled up with oil again, I rocked backwards and forwards whilst in gear with clutch held in and the rear wheel now moves freely ! Seems like it was just sticky plates!

I dared to start her in gear and clutch seems to be working as it should now, however there is a little clutch drag, I think it just needs running in as its been dry stood for so long.

I also checked the kick starter mechanism and it all looks fine to me... however it just doesnt seem to want to bite if I move the kickstart slowly. Am I just not "kicking" fast engough for it to bite? Video:

https://photos.app.goo.gl/5RRY3ikPwhp29te66

I did check the ratchet mechinism and it moves freely.

Cheers,

[Oddjob]

The splines on that kick start shaft look pretty bad. Are you sure it's not just spinning on the lever? Watch the centre shaft as you slowly kick and see if it's actually moving.

Make sure the springs are located properly as well or it won't work.

[K2-K6]

At least progress with the clutch, so half way there.

The kickstart, the loop's spring tab at top left in photo should be held stationary when installed as it's this that when you rotate the shaft will cause the engagement spiral (inside that gear) to push the two sets of teeth onto each other and then drive the gear that turns the engine.  Phew, that's a long sentence 

If that "tang" also rotates, then nothing happens. Held like that (out of the engine) if you rotate that tang it should show you the paired gear teeth come into engagement if you do that while holding the rest of that assembly static.

[zombie365]

*Update*

So tried the kickstart tonight and it's working perfectly!

The only thing I can think I might have done is not put the kickstart hairpin into the slot when fitting the mechanism into the engine. Not 100% sure this was the cause but it's the only thing I can think that I might have done.

All working now

Just got to figure a way to stop my clip ons from slipping on stanchions! But I have a different post for that 

Cheers all

[Oddjob]

If you can find a decent second hand one I'd advise changing the shaft as the splines will go eventually. The inner ring is almost useless as they are, that means the outer ring is carrying all the stress and they will fail in time. Either that or don't use it very often