Topic: 2nd gear issue

[750IV]

74 cb750k
When accelerating in second gear I'm getting what I describe as a slipping, engaging, slipping until I shift into third. All other gears are normal.
Anyone see anything suspicious in the pics? First pic is neutral and the next is in second.
I drained and strained the oil and found no metal particles. Bike is not a hi miler, 16k.
Any thoughts are appreciated.

[PeWe]

Sounds as a slipping clutch.
-Clutch lever correctly adjusted inside chrome cover? The stop screw should be tightened until stop, back 1/2 turn and lock with nut.
- Wrong oil with friction modifiers as car oils have?
- Clutch fiber plates bad or the pressure plate cracked which can happen when installed and tightened wrong.
- Clutch metal plates warped.

[750IV]

The clutch friction plates and metal plates measured at the correct thickness and no warped metal plates,
Adjustment is correct
I'm using oil without friction modifiers
Pressure plate not cracked.
I assume slipping clutch symptoms would be in other gears too  but the issue is only in second gear.
I should call it more of a banging rather than slipping. Sort of jumping in and out of gear.
Thanks for your reply.

[robvangulik]

Either a bent switch fork or worn dogs on the side of the gears. A slipping clutch would slip in all (the higher) gears.

[750IV]

This bike reportedly sat in poor storage for 30 some years. 
Any chance the gear is not sliding freely due to dirt or varnish build up or whatever that might be remedied with something added to the oil?
Just trying to avoid pulling the engine but I guess it might come to that.

[ekpent]

 Not super rare for 2nd gear to go bad on these. I had one that would just gently fall out into a false neutral under load. Rob mentioned the probable cause. Clutches slip more in the higher gears with their higher load. Nice looking bike,sorry your having a problem with her.

[HondaMan]

Yep, it sorta sounds like a bent "L" shifter fork. If this happens it makes the C2 gear just barely engage the C5 gear next to it, and it can jump between its cogs, sort of like a 'snatch' more than a 'slip'. It goes away in either 1st or 2rd gear. This often occurs when the bike falls over on the shifter side and something hits the shifter with the engine off, and it lays that way for a while (like overnight).

[evinrude7]

my guess is what rob mentioned.  not trying to sell you a silver bullet here but i highly recommend the clutch modification that hondaman lays out here.  http://forums.sohc4.net/index.php?topic=7190.0  another member (72hondacb750) posted their step by step version of it that was really good.    it includes changing out possibly worn o-rings in the oil pump as well as one behind the counter shaft oiler.  http://forums.sohc4.net/index.php?topic=78643.0  best of luck. 

[750IV]

Yep, it sorta sounds like a bent "L" shifter fork. If this happens it makes the C2 gear just barely engage the C5 gear next to it, and it can jump between its cogs, sort of like a 'snatch' more than a 'slip'. It goes away in either 1st or 2rd gear. This often occurs when the bike falls over on the shifter side and something hits the shifter with the engine off, and it lays that way for a while (like overnight).

Thanks, that's very informative.
Let me throw this out. I barely had enough room this winter to restore it let alone enough room to pull and disassemble the trans.
This is not a for sale ad but what is the general consensus on offering it knowing the trans issue? If you're gentle in second gear it doesn't do it.
I followed the 75 750 Planet blue one that sold Tuesday on BaT for $10,750 with a little higher mileage and aftermarket exhaust (mine has 341's).
How much of an adjustment would be appropriate?

[scottly]

Have you messed with the neutral switch? Does the neutral light function properly?

[750IV]

Have you messed with the neutral switch? Does the neutral light function properly?

I never touched the neutral switch and the light functions properly and it's very easy to find neutral.

[scottly]

When the trans "dogs" are worn, it will jump out of gear under acceleration, into a "false neutral", not in and out of gear, and it's difficult to get the trans back into gear. Did this happen before you disassembled the clutch? Why did you disassemble the clutch?

[750IV]

When the trans "dogs" are worn, it will jump out of gear under acceleration, into a "false neutral", not in and out of gear, and it's difficult to get the trans back into gear. Did this happen before you disassembled the clutch? Why did you disassemble the clutch?

It's not difficult to get it back into gear because It  stays in second until you go into third or back to first.
I never rode it until I finished the restoration the other day.
I dissembled the clutch just to make sure it was ok as with all the other adjustments I checked.
After all this one sat for many years.

[Kevnz]

My 500 did exactly that, jumping in and out of gear. Worn dogs jumping in and out of mesh.

[scottly]

I dissembled the clutch just to make sure it was ok as with all the other adjustments I checked.

This was before the problem started, or after?

[750IV]

I never rode it before I did the resto. because it wasn't rideable.
I bought it "as is"  in October and did all the work this winter.

[scottly]

You "fixed" the clutch before you ever rode the bike??

[scottly]

Does this part look familiar? If improperly installed, it can cause trans problems.

[750IV]

Yes because it wasn't rideable, no gas tank or electrics and bad 30 year old tires,
In the course of checking everything I wanted to make sure the clutch discs/springs etc, were ok, which they were.

[750IV]

Does this part look familiar? If improperly installed, it can cause trans problems.

It is installed correctly.
I don't know what the Japanese call it but as a retired Millwright it is known as a Bellville washer and I'm very familiar with it.
Thanks for your help.

[Don R]

 Sounds clutchy to me. Especially the part about it still being in second until it's shifted to 3 or 1.

[scottly]

Does this part look familiar? If improperly installed, it can cause trans problems.

It is installed correctly.
I don't know what the Japanese call it but as a retired Millwright it is known as a Bellville washer and I'm very familiar with it.
Thanks for your help.

It is Not a Bellville washer!

[PeWe]

That bike look really good!
A stock bike like that must be kept intact.
- The mentioned washer is mounted with the dome facing outwards?

[750IV]

That bike look really good!
A stock bike like that must be kept intact.
- The mentioned washer is mounted with the dome facing outwards?

Thanks for your compliment and yes, dome facing outward.
As long as it's in my hands it will remain intact but I'm leaning towards it showing up on BaT soon with a description of the trans issue.
I appreciate all of the help but as far as it being a clutch issue does it make sense that it only has the issue in second gear?

[PeWe]

It depends on the power engine has.
You'll feel the difference,  smooth slip or jerky movement by gearbox.

Drive chain OK, not too worn sprockets looking like a stormy sea and chain jump over the cogs...?

When my K6 had car oil of good brand in the 80's (Mobil 1)
It slipped when gearing to 5th at around 190kmh +WOT. I heard how it slipped, reduced throttle and wot again. It sounded like gearing to 6:th .

Same bike 2 years ago, slip on 2nd gear around 3000-3500 rpm. Much more torque with 1000cc.
That was the clutch lever with too little play. After that no chancing with 1/4 turn out. Always 1/2.

That bike is well worth to get this sorted.

In worst case open the cases with engine up-side down to fix eventual gear forks.
Before that: I should investigate if something with gearing mechanism inside the shifter cover can be involved.