Author Topic: Cb750 K1 Seat Adjustment?  (Read 758 times)

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Offline TideWater2

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Cb750 K1 Seat Adjustment?
« on: January 25, 2025, 08:40:11 AM »
I have swapped a couple seats back and forth and it is not working to well. Is there any adjustment in these? They are all Honda seats. The main problem is the latch is traveling to far down to work properly and the seat is low on the left side, all cockeyed. The latch won't release without pulling up hard on the seat, it pops up to the latch, then you can release the latch. It look like I need to add to the rubber mounts, but I have never seen anyone doing this or talking about it, I must be missing something.
2 - 1971 CB750 K1s

Offline newday777

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Re: Cb750 K1 Seat Adjustment?
« Reply #1 on: January 25, 2025, 09:11:02 AM »
If you don't have the rubber bumpers under the seat that is your problem.
Stu
Honda Parts manager in the mid 1970s Nashua Honda
My current rides
1975 K5 Planet Blue my summer ride, it was a friend's bike I worked with at the Honda shop in 76, lots of fun to be on it again
1976 K6 Anteres Red rebuilding project, was originally my brother's that I set up from the crate, it'll breath again soon!
Project 750s, 2 K4, 2 K6, 1 K8
2008 GL1800 my daily ride and cross country runner

Prior bikes....
1972 Suzuki GT380 I had charge of it for a year in 1973 while my friend was deployed and learned to love street riding....
New CB450 K7 after my friend returned...
New CB750 K5 Planet Blue, demise by ex cousin in law at 9,000 miles...
New CB750 K6 Anteres Red, to replace the totaled K5, I sold this K6 at 45k in 1983, I had heavily modified it, many great memories on it and have missed it greatly.....
1983 GL1100A, 1999 GL1500 SE, 1999 GL1500A

Offline newday777

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Re: Cb750 K1 Seat Adjustment?
« Reply #2 on: January 25, 2025, 09:13:02 AM »
The rubber bumpers set the height. There is no height adjustment. 
No one mention it because it is a given.
Stu
Honda Parts manager in the mid 1970s Nashua Honda
My current rides
1975 K5 Planet Blue my summer ride, it was a friend's bike I worked with at the Honda shop in 76, lots of fun to be on it again
1976 K6 Anteres Red rebuilding project, was originally my brother's that I set up from the crate, it'll breath again soon!
Project 750s, 2 K4, 2 K6, 1 K8
2008 GL1800 my daily ride and cross country runner

Prior bikes....
1972 Suzuki GT380 I had charge of it for a year in 1973 while my friend was deployed and learned to love street riding....
New CB450 K7 after my friend returned...
New CB750 K5 Planet Blue, demise by ex cousin in law at 9,000 miles...
New CB750 K6 Anteres Red, to replace the totaled K5, I sold this K6 at 45k in 1983, I had heavily modified it, many great memories on it and have missed it greatly.....
1983 GL1100A, 1999 GL1500 SE, 1999 GL1500A

Offline TideWater2

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Re: Cb750 K1 Seat Adjustment?
« Reply #3 on: January 25, 2025, 09:35:21 AM »
The rubber bumpers set the height. There is no height adjustment. 
No one mention it because it is a given.

All of the rubber bumpers are in place on all seats and look identical to each other.
2 - 1971 CB750 K1s

Offline denward17

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Re: Cb750 K1 Seat Adjustment?
« Reply #4 on: January 25, 2025, 09:43:03 AM »
Either the mounting points are bent or the seat pan has been twisted?

Offline Kevin D

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Re: Cb750 K1 Seat Adjustment?
« Reply #5 on: January 25, 2025, 10:22:21 AM »
Quote
They are all Honda seats
Got any photos?
The K1 was a 1 year only seat.
Distinguished by the piping path.
71 CB750 K1
104,000 miles
Original Owner
———past———
70 SL100/125/150
70 Candy BlueGreen CB 750 K0
————————————————-
Former Honda parts kid/counter kid/do all
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Offline Don R

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Re: Cb750 K1 Seat Adjustment?
« Reply #6 on: January 25, 2025, 11:08:51 AM »
It should have these rubber bumpers.
No matter how many times you paint over a shadow, it's still there.
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 You don't need a weatherman to know which way the wind blows.

Offline newday777

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Re: Cb750 K1 Seat Adjustment?
« Reply #7 on: January 25, 2025, 11:28:14 AM »
The rubber bumpers set the height. There is no height adjustment. 
No one mention it because it is a given.

All of the rubber bumpers are in place on all seats and look identical to each other.
Post pictures of all your seats, top, bottom , sides and ends. Something is fishy
Stu
Honda Parts manager in the mid 1970s Nashua Honda
My current rides
1975 K5 Planet Blue my summer ride, it was a friend's bike I worked with at the Honda shop in 76, lots of fun to be on it again
1976 K6 Anteres Red rebuilding project, was originally my brother's that I set up from the crate, it'll breath again soon!
Project 750s, 2 K4, 2 K6, 1 K8
2008 GL1800 my daily ride and cross country runner

Prior bikes....
1972 Suzuki GT380 I had charge of it for a year in 1973 while my friend was deployed and learned to love street riding....
New CB450 K7 after my friend returned...
New CB750 K5 Planet Blue, demise by ex cousin in law at 9,000 miles...
New CB750 K6 Anteres Red, to replace the totaled K5, I sold this K6 at 45k in 1983, I had heavily modified it, many great memories on it and have missed it greatly.....
1983 GL1100A, 1999 GL1500 SE, 1999 GL1500A

Offline Don R

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Re: Cb750 K1 Seat Adjustment?
« Reply #8 on: January 25, 2025, 02:41:23 PM »
 You are pinching the safety catch together aren't you, I wouldn't mention it except I observed a well-known supplier of our parts when he was unable to open the seat that he sold to me. I had to show him how to pinch the safety catch together. L0L!
No matter how many times you paint over a shadow, it's still there.
 CEO at the no kill motorcycle shop.
 You don't need a weatherman to know which way the wind blows.

Offline seanbarney41

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Re: Cb750 K1 Seat Adjustment?
« Reply #9 on: January 25, 2025, 03:06:17 PM »
The hinges have slotted bolt holes where the hinges bolt to the seat.  I have seen where if the latch does not line up just right it dpes not sit down all the way, also makes the bumpers not hit right, also the old bumpers I have seen have usually hardened into a compressed form,, so new bumpers may have to compress, also the hinge tabs on the frame bend easily so those may need to be bent nack into the correct place,,,
If it works good, it looks good...

Offline TideWater2

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Re: Cb750 K1 Seat Adjustment?
« Reply #10 on: January 25, 2025, 03:36:40 PM »
You are pinching the safety catch together aren't you, I wouldn't mention it except I observed a well-known supplier of our parts when he was unable to open the seat that he sold to me. I had to show him how to pinch the safety catch together. L0L!

Yes. I have two original seats on two K1s and the latch works as it should. When I put a NOS seat on is when I ran into the issue. The latch works fine, the fit is the problem.
2 - 1971 CB750 K1s

Offline TideWater2

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Re: Cb750 K1 Seat Adjustment?
« Reply #11 on: January 25, 2025, 03:38:03 PM »
The rubber bumpers set the height. There is no height adjustment. 
No one mention it because it is a given.

All of the rubber bumpers are in place on all seats and look identical to each other.
Post pictures of all your seats, top, bottom , sides and ends. Something is fishy

I'll try to get some good photos tomorrow. Thanks
2 - 1971 CB750 K1s

Offline TideWater2

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Re: Cb750 K1 Seat Adjustment?
« Reply #12 on: January 25, 2025, 03:42:55 PM »
The hinges have slotted bolt holes where the hinges bolt to the seat.  I have seen where if the latch does not line up just right it dpes not sit down all the way, also makes the bumpers not hit right, also the old bumpers I have seen have usually hardened into a compressed form,, so new bumpers may have to compress, also the hinge tabs on the frame bend easily so those may need to be bent nack into the correct place,,,

The seat is traveling down to far on the left/latch side. I will look at the hinges a little closer tomorrow when I take pics. Thanks
2 - 1971 CB750 K1s

Offline BenelliSEI

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Re: Cb750 K1 Seat Adjustment?
« Reply #13 on: January 25, 2025, 04:54:08 PM »
Check to see that all of the rubbers stops are landing squarely on the frame. The most forward pair should be shaped to land on the frame rails? This picture is an earlier KO seat, but I believe yours should look the same?

Any chance you have the hinge brackets on 180 degrees around the wrong way? I’ve done it and then all the pads miss the frame……
« Last Edit: January 25, 2025, 05:01:51 PM by BenelliSEI »

Offline TideWater2

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Re: Cb750 K1 Seat Adjustment?
« Reply #14 on: January 26, 2025, 12:30:18 PM »
I got some photo taken. All of the rubber bumpers measure out the same on both seats and are in the same spacing/location. I used the old latch because the new latch was way out of aliment despite looking identical by eye balling them. 
2 - 1971 CB750 K1s

Offline TideWater2

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Re: Cb750 K1 Seat Adjustment?
« Reply #15 on: January 26, 2025, 12:43:35 PM »
There is a slight difference in the hinges, but it sure don't look like enough to cause the seat to fit so poorly. The hinges spec out the same on both seats.
2 - 1971 CB750 K1s

Offline Ozzybud

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Re: Cb750 K1 Seat Adjustment?
« Reply #16 on: January 26, 2025, 01:17:11 PM »
Can you post a pic of the hinge mounts on the frame?
Also a pic of the seat mounted on the bike from a couple angles to show how it's not fitting.
Sounding like the mounts on the frame are bent.
Have you tried leaving the bolts on the seat mounts just barely tight so you can massage it around.
1976 Z50A YELLOW
1970 CT70 BLUE
1971 CT70H ORANGE
1972 CT70H GREEN
1973 CL200 BLUE
1973 CB350F RED
1975 CB360T RED
1975 CB400F BLUE
1975 CB550 ORANGE
1976 CB750F RED

Offline TideWater2

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Re: Cb750 K1 Seat Adjustment?
« Reply #17 on: January 26, 2025, 01:40:58 PM »
Can you post a pic of the hinge mounts on the frame?
Also a pic of the seat mounted on the bike from a couple angles to show how it's not fitting.
Sounding like the mounts on the frame are bent.
Have you tried leaving the bolts on the seat mounts just barely tight so you can massage it around.

Here is photos of the mounts on the bike. I would think if they were bent, both seats would not fit. It will probably be tomorrow before I get the pics of the seat remounted.
2 - 1971 CB750 K1s

Offline Ozzybud

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Re: Cb750 K1 Seat Adjustment?
« Reply #18 on: January 26, 2025, 03:03:54 PM »
Can you post a pic of the hinge mounts on the frame?
Also a pic of the seat mounted on the bike from a couple angles to show how it's not fitting.
Sounding like the mounts on the frame are bent.
Have you tried leaving the bolts on the seat mounts just barely tight so you can massage it around.

Here is photos of the mounts on the bike. I would think if they were bent, both seats would not fit. It will probably be tomorrow before I get the pics of the seat remounted.

You stated that both the seats fit poorly. That leads me to believe that its not the seats.

Someone stated earlier that your bike is a one year only for the seat. Are we sure they are correct for your bike?
1976 Z50A YELLOW
1970 CT70 BLUE
1971 CT70H ORANGE
1972 CT70H GREEN
1973 CL200 BLUE
1973 CB350F RED
1975 CB360T RED
1975 CB400F BLUE
1975 CB550 ORANGE
1976 CB750F RED

Offline TideWater2

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Re: Cb750 K1 Seat Adjustment?
« Reply #19 on: January 27, 2025, 06:41:44 AM »
Can you post a pic of the hinge mounts on the frame?
Also a pic of the seat mounted on the bike from a couple angles to show how it's not fitting.
Sounding like the mounts on the frame are bent.
Have you tried leaving the bolts on the seat mounts just barely tight so you can massage it around.

Here is photos of the mounts on the bike. I would think if they were bent, both seats would not fit. It will probably be tomorrow before I get the pics of the seat remounted.

You stated that both the seats fit poorly. That leads me to believe that its not the seats.

Someone stated earlier that your bike is a one year only for the seat. Are we sure they are correct for your bike?

Ozzybud,

I wasn't very clear about the seats. The original fits fine, but fitting a NOS seat is not fitting very good. Sorry.
2 - 1971 CB750 K1s

Offline bryanj

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Re: Cb750 K1 Seat Adjustment?
« Reply #20 on: January 27, 2025, 07:33:15 AM »
Is the new seat an aftermarket with plastic base?
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Offline TideWater2

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Re: Cb750 K1 Seat Adjustment?
« Reply #21 on: January 27, 2025, 07:42:26 AM »
Is the new seat an aftermarket with plastic base?

No, it is a Honda NOS seat.
2 - 1971 CB750 K1s

Offline 69cb750

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Re: Cb750 K1 Seat Adjustment?
« Reply #22 on: January 27, 2025, 08:12:37 AM »
Quote
I have swapped a couple seats back and forth and it is not working to well. Is there any adjustment in these? They are all Honda seats. The main problem is the latch is traveling to far down to work properly and the seat is low on the left side, all cockeyed. The latch won't release without pulling up hard on the seat, it pops up to the latch, then you can release the latch. It look like I need to add to the rubber mounts, but I have never seen anyone doing this or talking about it, I must be missing something.

I have added washers between seat and latch to get the seat level and latch latching.