Topic: Restricted to 1st gear and Neutral only

[CB500FK0]

I went for a short Sunday ride to grab some coffee. Everything was functioning perfectly until it was time to head back home. At that point, I was only able to engage first gear or set it to neutral. I couldn't shift into the higher gears anymore. I've already checked the oil level, clutch cable, clutch lever free play (which is within spec), as well as the clutch adjuster. I removed the crankcase cover and I didn't see any abnormal except I might need to replace the spring. Despite my efforts, I'm at a loss for what else to inspect. Any suggestions or recommendations would be greatly appreciated.

[Andey108]

Not sure if it’s what’s happening in your case, but had the same happen to me.

But I pretty much had this happen from me owning my bike, so I have nothing to compare it to.

But my clutch wasn’t separating, clutch springs were gone. Swapped the springs and plates and solved my problem.

Also took me a while to figure out the clutch actuator worm drive on the end of the cover. How rotating it gives you more throw at the lever. The PO abused mine so ended up with a very specific position where it would work with the clutch. Any turns clockwise or anticlockwise wouldn’t work…

[Shtonecb500]

my buddy is dealing with this right now on his bike, when its running he gets into first but it wont shift back into neutral or second....when the bike is off the bike shifts fine.

[grcamna2]

Could be clutch/adjuster.

The gearshift spindle may have gotten hit and not properly engaging the shift drum somehow;did the bike fall over on the left side?

[CB500FK0]

@grcamna2, that was the first thing checked. The dilemma is why 1st and neutral still work perfectly fine, but not the upper gears.

[newday777]

Welcome to the forum CB500FK0

Is this a new bike to you, new build and 1st ride discovery? Or was it working properly and is a new situation occurring?
You haven't given us much for details on your bike.

Do you have rear sets on your bike? Does the shift lever have full motion? It looks to be too close to the case cover Allen bolt and may be restricted in movement???

Go to the new members introduction section and introduce yourself and your bike.

[CB500FK0]

Hello @newday777,

This bike is not new to me, nor is it a new build or a discovery on the first ride. Yes, it was working properly, so this is a new situation that has arisen.

It has Tarozzi rearsets with a full-motion shift lever, which wasn't a problem before. It is indeed close to the case but not to the Allen bolt so it's operational.

New members introduction ✅

[grcamna2]

Welcome to the forum CB500FK0

Is this a new bike to you, new build and 1st ride discovery? Or was it working properly and is a new situation occurring?
You haven't given us much for details on your bike.

Do you have rear sets on your bike? Does the shift lever have full motion? It looks to be too close to the case cover Allen bolt and may be restricted in movement???

Go to the new members introduction section and introduce yourself and your bike.

+1 on "Does the shift lever have full motion"?  The shift lever could be binding somehow?

[CB500FK0]

+1 on "Does the shift lever have full motion"?  The shift lever could be binding somehow?

Yes, it does have full motion without any binding.

[newday777]

Hello @newday777,

This bike is not new to me, nor is it a new build or a discovery on the first ride. Yes, it was working properly, so this is a new situation that has arisen.

It has Tarozzi rearsets with a full-motion shift lever, which wasn't a problem before. It is indeed close to the case but not to the Allen bolt so it's operational.

New members introduction ✅

Then you will have to remove the cover and inspect the shift ratchet. Maybe the spring has come off.

[CB500FK0]

Perhaps this video can help to evaluate the issue or at the very least reveal something unusual. Thank you in advance for your help!🙏

[grcamna2]

Pull/slide the complete clutch assembly off of the mainshaft and have a closer look behind it at the shift drum and shifter linkage.

[CB500FK0]

Pull/slide the complete clutch assembly off of the mainshaft and have a closer look behind it at the shift drum and shifter linkage.

I removed the entire clutch assembly. Let me know you are able to identify the problem.

[bryanj]

 That is a VERY early 500 with the original gearchange/detent system, go to the uk site and look in lladins cave or ash's dropbox for the sevice bulletin about that.
The very early bikes had bad needle roller bearings on one of the gearshafts which broke up and also caused bad shifting plus gearbox lock up.

Now the most cost effective way to get the parts you need will be a complete engine

[RAFster122s]

RB has a bunch of cb500s, maybe he has some spares that could fix your issues, he posted today…
Forget his full user ID.

[dave500]

maybe look for a 550 motor,improved transmission and clutch etc,your top end will go onto it,youll need the right hand rear engine mount aswell it holds the clutch cable,and youll need the correct clutch cable.

[RAFster122s]

Dave's suggestion is a far better one...clutch and any gearbox issues addressed in 550. Fit the 77-78 pinned rocker shafts cover and you have the best of all worlds for the 500/550 size SOHC4 motor. Great handling.
I would suggest fitting a cb650 motor but some parts for rebuild are difficult to obtain...

[pekingduck]

Not saying it's the cause, but it is the first thing I'd look at.  The way this Tarozzi rear set gear shift pivot is mounted is wrong by design.  When that ball and socket pivot is mounted like that, it has a limited range of motion before the mounting stud of the ball hits the edges of the socket.  That pivot is meant to be mounted at a right angle, giving it an unlimited range of rotation.

[grcamna2]

Pull/slide the complete clutch assembly off of the mainshaft and have a closer look behind it at the shift drum and shifter linkage.

I removed the entire clutch assembly. Let me know you are able to identify the problem (video below). TIA!

The top forked part(the shift drum stopper)that engages into the shift drum on the right w/ spring;I'm looking at the mounting bolt where it slides in and out. Check that mounting bolt to see if it's hanging-up the steel arm on the bolt,rather than springing back into position:I would want that part to move Very freely to the left and right with the least amount of friction.
The spring might need adjustment too..

[CB500FK0]

The top forked part that engages into the shift drum on the right w/ spring;I'm looking at the mounting bolt where it slides in and out. Check that mounting bolt to see if it's hanging-up the steel arm on the bolt,rather than springing back into position:I would want that part to move Very freely to the left and right with the least amount of friction.
The spring might need adjustment too..

@grcamna2, are you referring to the bolt indicated with yellow arrow below?

[grcamna2]

The top forked part that engages into the shift drum on the right w/ spring;I'm looking at the mounting bolt where it slides in and out. Check that mounting bolt to see if it's hanging-up the steel arm on the bolt,rather than springing back into position:I would want that part to move Very freely to the left and right with the least amount of friction.
The spring might need adjustment too..

@grcamna2, are you referring to the bolt indicated with yellow arrow below?

Yes,that entire assembly with bolt,spring,etc. 
Make that 'shift drum stopper' part and the 'shift drum pins' (the shift drum pins are at the ends of each point on the 'star') which it engages in that end of the shift drum work as smoothly as you can.

[CB500FK0]

While removing the shift drum stopper assembly and shift drum guide screw, I noticed that the latter was missing the spring and the cap (#1 and #23 below). I have ordered both to see if that makes a difference.

[grcamna2]

Ok,good.
What condition are the 5) pins in? I hope they're still round.

[CB500FK0]

That pivot is meant to be mounted at a right angle, giving it an unlimited range of rotation.

@pekingduck, The previous owner installed the Tarozzi rear sets, and for several weeks, the shifting was working fine. However, I concur that something doesn't appear quite right. Would you happen to have any pictures showing them mounted at a proper right angle? TIA!

[CB500FK0]

Ok,good.
What condition are the 5) pins in? I hope they're still round.

Are you referring to the pins below? If so, then there are only 4 pins and they look good.