Clutch issue on my 1978 Honda CB550

[aleix84]

Hi all,

I recently purchased a 1978 Honda CB550 (in-line 4) and I've always had a (hopefully) mild issue with the clutch. I recently found out about this forum and the vast amount of knowledge that you guys have on these types of bikes.

When I put it in first and start letting go of the clutch, it looks as though it's struggling a bit but then, there's a very mild jerk and you notice the gear is then fully engaged. It only happens in first gear. I bought a new clutch, which I'm aiming to replace soon. Am I barking at the wrong tree here? Is it something else?

In addition to that, the bike really struggles to go into neutral when stationary. I thought I'd be clever and tighten the clutch cable. When I did that, getting into neutral was much easier, but then the gears started jumping when accelerating, bringing the bike into a weird neutral (like between 2nd and 3rd, or between 3rd and 4th gear type thing). Is it a cable problem? Is it the clutch springs not doing their job? Is it something completely different?

I look forward to your help here, and apologies if this has been discussed here before. I tried to look threads discussing this problem but couldn't find anything.

Thanks in advance for your time

 

[ancientdad]

There's a significant difference between clutch slippage and jumping in and out of gear, so a video might help. Clutch slippage happens when the engine rpms go up significantly but the bike isn't accelerating according to the engine speed. Clutch slippage can be solved, clutch adjustment is key to both avoiding slippage on a clutch in good condition and getting the engine into neutral easily. Minor clutch adjustments can be made at the clutch lever or at the lower end of the cable at the right crankcase cover, but there's also a clutch adjuster in the right crankcase cover.



The clutch cable is connected to the clevis at the end of #4, and the lock nut goes on the end of the adjuster screw on #7. The adjuster screw and lock nut is in the cover here (CMSNL had the picture upside down)

 

[EzPete]

It really sounds like you're not getting completely into gear moreso than a clutch issue. If you don't already have a manual, HERE IS ONE.
Page 12 is the proper clutch adjustment process. Do this first.

Then, I'd play with the orientation of the shift lever. You may find that rotating the lever on the shaft a spline or two in either direction solves the issue by aligning the geometry/leverage better for you.

If both of those do nothing, then it's time to pop the clutch off and take a look - starts on page 40. Don't forget to get a replacement gasket for the side cover (part number 11394-390-306)

 

[aleix84]

There's a significant difference between clutch slippage and jumping in and out of gear, so a video might help. Clutch slippage happens when the engine rpms go up significantly but the bike isn't accelerating according to the engine speed. Clutch slippage can be solved, clutch adjustment is key to both avoiding slippage on a clutch in good condition and getting the engine into neutral easily. Minor clutch adjustments can be made at the clutch lever or at the lower end of the cable at the right crankcase cover, but there's also a clutch adjuster in the right crankcase cover.

View attachment 59727

The clutch cable is connected to the clevis at the end of #4, and the lock nut goes on the end of the adjuster screw on #7. The adjuster screw and lock nut is in the cover here (CMSNL had the picture upside down)

View attachment 59728

Thank you so much, that's very helpful. I had no idea there was a clutch adjuster in the crank cover. So far I've only played with the adjuster at the lever, but never on the bottom end of the cable, let alone through the clutch cover. I will start trying different settings via these adjustment tools before I go too deep opening the clutch cover and checking the actual clutch.

 

[aleix84]

It really sounds like you're not getting completely into gear moreso than a clutch issue. If you don't already have a manual, HERE IS ONE.
Page 12 is the proper clutch adjustment process. Do this first.

Then, I'd play with the orientation of the shift lever. You may find that rotating the lever on the shaft a spline or two in either direction solves the issue by aligning the geometry/leverage better for you.

If both of those do nothing, then it's time to pop the clutch off and take a look - starts on page 40. Don't forget to get a replacement gasket for the side cover (part number 11394-390-306)

Thanks EzPete, I started reading the manual (which I didn't have, thank you so much). I bought a new clutch and side cover gasket. but I think there's quite a lot I can check before that. I'll definitely start adjusting the clutch and see if that improves things.

Thanks a lot.

PS: love the bike in your profile picture!

 

[EzPete]

Thanks EzPete, I started reading the manual (which I didn't have, thank you so much). I bought a new clutch and side cover gasket. but I think there's quite a lot I can check before that. I'll definitely start adjusting the clutch and see if that improves things.

Thanks a lot.

PS: love the bike in your profile picture!

Thanks man - that bike has been a particularly interesting journey.

For your clutch issue, always best to start on the stuff that doesn't involve removing gaskets when you can. One thing I forgot to ask - what kind of oil are you running in the bike? Is there any clutch material or gunk in the filter when you change it?

Definitely take a look at altering the lever position - if it's too "low" it makes the leverage more of a pull against the spline and less of a rotation.

 

[Cycleranger]

If you do not have a shop manual for your bike you can go here:

Documentazione Tecnica

Sito dedicato alle Honda CB Four degli anni settanta.

www.honda4fun.com

And download PDF's of the Honda shop manual and the parts list. (Don't worry, the manuals are in English.)
You will find them immensely helpful.
You might also pop over and check out the Honda SOHC4 forums for more info about your CB550.

https://forums.sohc4.net/