CB350 Shifting issues

[sbelshe]

Recently my 72 CB350 has developed some shifting issues.

1. The bike has a hard time finding neutral. I have to be so delicate between 1st and 2nd, often going back and forth a few times before I can finally hit it. It didn't used to be that hard, it seems to almost have no actual "slot", it's seems to be more of just a lucky guess to hit the spot in passing.

2. More importantly, the bike has trouble downshifting about 25% of the time. No problem up shifting, but when going down, it feels like the clutch isn't engaged. Feels the same as it does if your in first then try to go down further. If I let the clutch out then the pull it again, then it will shift down again, but sometimes only one gear.

The cable is only a few months old, and I messed around a bit with the cable adjustment to no avail. I also feel like no matter what I do, the bolt the clutch cable goes through on the top of the case never get very tight

Any other ideas? Thanks a lot.

 

[DoubleClutch]

Sounds like to me that your clutch plates are hanging up and not fully separating. But what am I to now just a guess!

 

[Redliner]

It may be a worn or loose shift-drum. Funny, but sometimes disassembling this drum and putting the forks back on it can solve this issue. But being able to actually move the shift lever makes me hopeful that we won't split the case.

First check the clutch. Put the bike on a wheel-stand or the center-stand. Start the bike and put it in first, or really any gear you can reach : all while holding the clutch lever in. The wheel should begin to turn a bit, but tap the rear brake lever and let go. Did the engine hesitate or stall? Does the tire continue to turn once you let go? If so, your clutch is still engaging.

You'll have to replace your clutch-cover gasket if you do the following.

Remove the clutch cover and observe the shift-arm that is actuated by the shift-spindle. It has a sort of "claw", one V-groove on each end. As you shift up or down, this should engage the pins on the shift drum. Any apparent problems on this side? Try to move the shift drum. Does the shift drum move in any direction?

As for neutral, it's engaged by a ball on the top of the drum. Look at your crankcase. On top there is a fat bolt with a lock-washer securing it. It's near where the clutch cable goes in. It's possible the ball/spring in this bolt are binding or the ball has somehow broken. Check this.

Whatever you do, don't hit the shifter harder. It causes even more problems.

 

[Rich Ard]

Follow these directions first and let us know how it goes from there:

http://www.hondatwins.net/forum/viewtopic.php?t=8963

 

[Bert Jan]

did you do an oil-change recently?

 

[sbelshe]

I followed the steps on the clutch adjustment link, that seems to have solved most of the problem. I had done this before, just not correctly. The steps I followed to adjust the case screw didn't involve lossening the cable first, that was the key. I still have a bit of a tough time location neutral but the downshift issue is much better.

I did recently do an oil change, curious why you would ask?

Thanks everybody

 

[Scruffy]

Because the wrong oil in a vintage engine leads to a lot of problems. Clutch can get loaded up with friction modifiers to the point of sticking or constant slippage, frying the frictions and steels. Can also cause the top end of your engine to give out, oil without enough zddp in it will let the cam lobes and cam followers that actuate your valves grind each other down.

For stateside riders of vintage wet clutch machines, the two most common correct oils are Rotella T 15W40 conventional, and Rotella T6 5W40 synthetic. There are decent oils from Amsoil, Mobil, Redline, Klotz, etc, but they run 2-5x the cost of Rotella. You can even use Super Tech 15W40, has a higher zinc content than Rotella, but also has more of a few detrimental components (found in ALL oils after a couple runnings).

Clear as mud, right? Go to www.suzukisavage.com, then the rubber side down or the tech board sections and look for the oil wars threads, or the recommended oils threads. Applies equally to older Hondas, same cam followers.

 

[sbelshe]

I'm running Mobile 1 10w40 (what the bike recommends) wet clutch. I had read alot of posts on what oil to use and so many people said any 10w40 wet clutch would work I went with it. Interesting to hear someone have such specifics on alternatives, I really appreciate it!

 

[Scruffy]

We put motorcycle synthetic 10W40 in my bike, once. Within 10 miles it quit shifting. Been running big rig spec 15W40 since then. Took 5 oil changes to get the clutch working properly again, takes awhile for the plates to flush out the additives and carbon build up.

I used to get a lot of vintage bikes in that ran Castrol Actevo oil. That stuff is bad news, works fine in a liquid cooled bike, sometimes, others it fries the clutch. Had to replace a 1500 Drifter clutch with only 85K miles on it, still had half its friction lining thickness, but was so glassy it wouldn't engage. Took an hour to get the steels clean and rough enough to work properly.

Ask Kopcicle, he knows me and the Drifter owner (Doug) from when we all worked near each other a few years ago. Our bikes get flogged pretty good.

 

[Redliner]

Have you tried the bike on the center-stand to see if the clutch is sticking? :

 

[sbelshe]

Not yet. I had taken my center stand off so I'll have to put it back on to do so.

 

[Redliner]

Generally you can see if it's sticking or slipping without putting the wheel up, but picking up the rear wheel can allow you to do a little more testing. Like trying to turn the rear wheel backwards with the clutch lever in.

Without picking the bike up, you can put it in first and roll backwards with the clutch in. Do you feel any resistance vs. neutral? Does the engine stumble or change RPM when shifting from neutral to first?

If it's slipping, you can sorta get an idea by sloooowly taking off to feel exactly when the clutch engages and starts to roll. We're rolling around with the clutch just barely engaged enough to do so. Now do the exact same take-off but use your legs to hold the bike from rolling. Now let the clutch out a bit more. You should take off.

This is how I launch from a stop-light when I feel like breaking a few laws. Roll throttle to about 3k, let the clutch out very slowly until I feel it pull. Then pull it in a hair and rev up to 5-7k. This way when I launch it's like popping the clutch but with both wheels firmly planted

I say that to say this, at 3k the engine pulling with the clutch just engaged feels like sitting on a steep hill. Letting the clutch out a hair-more will begin to drag your shoes out from beneath you.

Still sounds like a transmission/shifter issue to me, since you say it feels like hitting below first.

Another member seems to have solved a similar issue with shifting feeling like hitting nothing.

http://www.dotheton.com/forum/index.php?topic=51518.msg579916#msg579916

 

[sbelshe]

I do have a bit of resistance while rolling in neutral, and as far as the engine stumbling when I shift into first, it does a little but I can't tell yet if thats a related issues because another problem I have is my bike rev's higher when I pull in the clutch.