Author Topic: Has my K0 engine (shifter) been assembled wrong? (Read 1236 times)

jebon · « **on:** September 20, 2020, 02:47:14 PM »

So on the first test ride on my newly acquired K0 I notice that it doesn't go into 3rd gear. After inspecting the shifter and comparing with the Hackaweek episode I conclude that something is assembled wrong. I hope that it is in the shifter mechanism and not the shifter rod that goes to the gears. Someone who has taken a CB750 engine apart, please please take a look at this.

Please notice that the plate disc to keep it in gear only engages correctly in 1st and 2nd gear. When pulling for 3rd gear, it doesn't engage and the pull arm can't move it further.

My video

Hackaweek

(10.15)

Please tell me the engine won't have to be taken apart to fix this

Thanks,
Jess

trigger · « **Reply #1 on:** September 20, 2020, 03:16:24 PM »

you have to turn the output shaft to engage gears. Also make sure the wheel is sitting on the grove of the selector drum

jebon · « **Reply #2 on:** September 20, 2020, 03:33:24 PM »

Quote from: trigger on September 20, 2020, 03:16:24 PM

you have to turn the output shaft to engage gears. Also make sure the wheel is sitting on the grove of the selector drum

Which one is the output shaft? (sorry, I'm Danish). It did the same when I rode it.
I'm not sure I get it. You do not think the selector drum is rotated wrong?

robvangulik · « **Reply #3 on:** September 20, 2020, 04:10:08 PM »

The shaft where the sprocket for your chain sits on. You should rotate it while shifting.

Old Moe Toe · « **Reply #4 on:** September 20, 2020, 04:22:26 PM »

Your shift mechanism looks to be put together correctly from what I can see.
As it happens, I assembled mine yesterday after an engine re-build.
Here are a couple of pics for your perusal.
What is the story with your KO?. It is disappointing it does not go into 3rd gear on your first ride. Were you not allowed to take it for a test ride before you bought it?.
Cheers
Brad

69cb750 · « **Reply #5 on:** September 20, 2020, 04:22:58 PM »

Install sprocket. Spin sprocket forward while shifting gears.
Shifter only works with sprocket spinning.

70CB750 · « **Reply #6 on:** September 20, 2020, 05:21:10 PM »

I dealt with shifting problems with Red, here is more info:

http://forums.sohc4.net/index.php?topic=147098.50

Read on what Hondaman posted.

After all this said and done I found out the shifting problem was directly related to the cover bolt right by the shifter. I used hondabond because I did not have the paper gasket and cranking down that bolt would stop it from shifting. If I kept that bolt looser, it shifted perfectly. After I installed paper gasket, this problem completely disappeared, seems like it needs the paper for proper spacing and to keep the shift cover from flexing/bending.

Long story short, I would put my money on the cover if the linkage is assembled correctly.

jebon · « **Reply #7 on:** September 20, 2020, 09:37:06 PM »

I'll give it a try but it acts the same with and without the cover. Moving and at still stand. Note that it also doesn't go correctly into 1st.

754 · « **Reply #8 on:** September 20, 2020, 10:08:21 PM »

There is a change in the shifter mechanism around 26,×××.. not sure I'd shift drum is same on all motors.

jebon · « **Reply #9 on:** September 21, 2020, 12:44:41 AM »

Quote from: 754 on September 20, 2020, 10:08:21 PM

There is a change in the shifter mechanism around 26,×××.. not sure I'd shift drum is same on all motors.

Mine is 42xxx. I think it's the same as the Hackaweek one

jebon · « **Reply #10 on:** September 21, 2020, 05:19:51 AM »

All gears work when I turn the wheel

Will try and see if shifting when driving works with a slightly looser cover

754 · « **Reply #11 on:** September 21, 2020, 09:30:47 AM »

Just so you know, working on tranny involves splitting the cases..
But SOP is......remove engine sidecovers, leave alternator and clutch on.
Undo top case bolts, then flip engine upside down and block it up.
Then lower case bolts , and split cases... not really as bad as it sounds..
If shifter forks were not lined up correctly, it could prevent shifting..
That IS why you Always. .always .. roll thru the gears and check that they are all there.. before bottoming up the rest. .

JohnN · « **Reply #12 on:** September 21, 2020, 09:48:52 AM »

Inspect the shift arm closely before you split the cases. A weak spring can cause that problem as well as a bent or binding pivot point. Remove the spring and make sure it moves easily.
John

754 · « **Reply #13 on:** September 21, 2020, 10:50:43 AM »

Keep in mind when trying toshift thru gears with cover off, that the shifter shaft is flopping all over the place..

jebon · « **Reply #14 on:** September 21, 2020, 11:27:30 AM »

Paper gasket ordered. Will try with cover on, loser bolts around the shifter lever

Thanks!

jebon · « **Reply #15 on:** September 25, 2020, 07:23:17 AM »

Update:
Mount shifter cover BEFORE the stator cover.
In my case the shifter rod was pinched because of this

754 · « **Reply #16 on:** September 25, 2020, 07:31:38 AM »

Ummmmm, are you missing the dowels ?

jebon · « **Reply #17 on:** September 25, 2020, 07:49:03 AM »

Quote from: 754 on September 25, 2020, 07:31:38 AM

Ummmmm, are you missing the dowels ?

No, everything is fine

754 · « **Reply #18 on:** September 25, 2020, 10:33:24 AM »

If it has 2 dowels it can't move , either cover can then go on first.
I suspect gasket thickness may be the cause...

Medyo Bastos · « **Reply #19 on:** September 25, 2020, 11:28:26 AM »

There was a honda recommended mod for the drum stopper that should have been a recall -> turn down the OD by 1.5mm, and weld the detent notch smooth.

Part 1-1

I’ve never had an issue since doing this mod. This is something I read on here several years ago. I will try and find the original post.

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Author Topic: Has my K0 engine (shifter) been assembled wrong? (Read 1236 times)