Author Topic: Are there CB750 K1-K6 Frame Physical Differences??  (Read 1034 times)

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Online newday777

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Are there CB750 K1-K6 Frame Physical Differences??
« on: May 21, 2023, 05:47:42 PM »
Well I went to a swap meet today and bought a NOS USA replacement frame, no numbers stamped on it, no holes for the vin plate and still in the plastic Honda parts bag. The guy said that he bought it along a bunch of other parts from a Honda dealer in CT that was selling off their unused parts inventory. He thinks it was for a K1-K2. But looking at the seat latch mount I'm thinking it might be K2, or does the K1 seat latch(no lock, pull type) mount with the same holes as the K2-K6 lock latch? I've not seen a K0-K1 frame to compare.
I just looked up the part numbers on CMSL, the K1 has a 300 frame number. K2-K6 have 341 frame numbers.
The K2 has different last 3 numbers than K3-K5, and K6 has different last 3 numbers even again.
1. Anyone aware of physical differences between the years?

2. Anyone have the Honda stamp set, letters and numerals, that I could use to stamp this frame to the one I have that is rusted(deep pits from mice pee,). I have the vin tag and title for(it was my dad's bike)?

I managed to strap it on the back seat of my wing for the 60 mile return trip back to my shop.  8)
« Last Edit: May 21, 2023, 05:53:42 PM by newday777 »
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 HondaMan

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Re: Are there CB750 K1-K6 Frame Physical Differences??
« Reply #1 on: May 21, 2023, 10:44:24 PM »
You're on the right track with the seat latch: the K0/1 frames were different under the seat from the K2/6 versions. The K3-6 versions had the main wire harness ground at the front coil's mount (bared of paint there) while the K2 had it at the middle of the bike, on the seat latch. The K0/1 also have it at the middle of the bike. Once in a while I have also seen some K4 bikes with the ground lug at the seat latch, not sure 'why'?

The K0/1 frames often needed drain holes drilled (7/64" or 1/8" drill) just forward of the lower front engine bolsters, both sides, as the lower bolsters are set deeper into the frames than are the later ones. The K0/1 frames also sometimes have a fully-welded plate at the junction of the middle downtubes to the lower cradle, with no open holes there. Some were corrected in the later "New Factory" K1 frames, but most needed a similar drain hole below those plates for seepage and condensation to drain out behind the rear lower bolsters.

The K2-6 frames were made with thicker, less-easily-corroded steel, too, but that is hard to tell from 'outside'. The mounting plate for the lower front right engine mount will fit both versions of the frame, but you might find a 1mm misalignment (I forget if it was 'up' or 'down') for the engine when a K2-6 triangle engine mount is used at the lower right site. A K0/1 mounting plate will cure that, but so will a drill...
See SOHC4shop@gmail.com for info about the gadgets I make for these bikes.

The demons are repulsed when a man does good. Use that.
Blood is thicker than water, but motor oil is thicker yet...so, don't mess with my SOHC4, or I might have to hurt you.
Hondaman's creed: "Bikers are family. Treat them accordingly."

Link to Hondaman Ignition: http://forums.sohc4.net/index.php?topic=67543.0

Link to My CB750 Book: https://www.lulu.com/search?adult_audience_rating=00&page=1&pageSize=10&q=my+cb750+book

Link to website: www.SOHC4shop.com

Offline Gurp

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Re: Are there CB750 K1-K6 Frame Physical Differences??
« Reply #2 on: May 21, 2023, 10:57:48 PM »
Im just here to say. Man I bet you got some looks making that haul!!!

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Offline PeWe

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Re: Are there CB750 K1-K6 Frame Physical Differences??
« Reply #3 on: May 21, 2023, 11:41:07 PM »
Perfect frame paint example. ;)
Is it glossy black?
Nice price for a new frame.

Like a complete bike with good frame but in need of new parts to hang on.
« Last Edit: May 21, 2023, 11:44:00 PM by PeWe »
CB750 K6-76  970cc (Earlier 1005cc JMR Billet block on the shelf waiting for a comeback)
CB750 K2-75 Parts assembled to a stock K2

Updates of the CB750 K6 -1976
http://forums.sohc4.net/index.php/topic,180468.msg2092136.html#msg2092136
The billet block build thread
http://forums.sohc4.net/index.php/topic,49438.msg1863571.html#msg1863571
CB750 K2 -1975  build thread
http://forums.sohc4.net/index.php/topic,168243.msg1948381.html#msg1948381
K2 engine build thread. For a complete CB750 -75
http://forums.sohc4.net/index.php/topic,180088.msg2088008.html#msg2088008
Carb jetting, a long story Mikuni TMR32
http://forums.sohc4.net/index.php/topic,179479.msg2104967.html#msg2104967

Offline bryanj

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Re: Are there CB750 K1-K6 Frame Physical Differences??
« Reply #4 on: May 21, 2023, 11:55:46 PM »
Stamps i dont think you will find as Honda never supplied them to dealers, at least not in uk.
Thats one way you tell a new frame or cases, numbers may look same but letters never do
Semi Geriatric ex-Honda mechanic and MOT tester (UK version of annual inspection). Garage full of "projects" mostly 500/4 from pre 73 (no road tax in UK).

Remember "Its always in the last place you look" COURSE IT IS YOU STOP LOOKIN THEN!

Online newday777

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Re: Are there CB750 K1-K6 Frame Physical Differences??
« Reply #5 on: May 22, 2023, 03:12:35 AM »
You're on the right track with the seat latch: the K0/1 frames were different under the seat from the K2/6 versions. The K3-6 versions had the main wire harness ground at the front coil's mount (bared of paint there) while the K2 had it at the middle of the bike, on the seat latch. The K0/1 also have it at the middle of the bike. Once in a while I have also seen some K4 bikes with the ground lug at the seat latch, not sure 'why'?

The K0/1 frames often needed drain holes drilled (7/64" or 1/8" drill) just forward of the lower front engine bolsters, both sides, as the lower bolsters are set deeper into the frames than are the later ones. The K0/1 frames also sometimes have a fully-welded plate at the junction of the middle downtubes to the lower cradle, with no open holes there. Some were corrected in the later "New Factory" K1 frames, but most needed a similar drain hole below those plates for seepage and condensation to drain out behind the rear lower bolsters.

The K2-6 frames were made with thicker, less-easily-corroded steel, too, but that is hard to tell from 'outside'. The mounting plate for the lower front right engine mount will fit both versions of the frame, but you might find a 1mm misalignment (I forget if it was 'up' or 'down') for the engine when a K2-6 triangle engine mount is used at the lower right site. A K0/1 mounting plate will cure that, but so will a drill...

Thank you Mark that is helpful direction.
So the slide latches of the K0-K1 have different bolt patterns than the K2-K6? I haven't had any K0-K2 to work on to know them but have a friend @60 miles away with a couple of K1s that I could ride over and compare and another friend with a K2 @40 miles from me.
Were the harness  ground wire lugs bolted to the seat latch bolts and coil mounting bolts or with a separate bolt thread/hole in the frame specific for the grounds?
In 2020, stuck in San Diego, I stripped a K4 frame and painted it for a friend's bike. I do remember there being a ground lug at the seat latch area, but I think I remember there being a ground lug at the coils too, but my memory isn't real clear on that point nor do I have any pictures of the coil area showing the ground there. The seat latch area pictures don't really show where the ground is bolted at in my picture.
I have a couple K4s and K6s along with my K5 in my shop to look at to investigate the ground wire lugs and measure later in the week when I get back in the shop.

Gurp
Yes I had a couple onlookers while I was strapping it on the bike and a few puzzled looks from passing bikes on the road.

Yes Per the paint is mostly perfect with a couple spots needing touching up from storage scuffs. It put a glimmer in my eye as I looked it over through the holes in the plastic Honda parts bag.
It's not what I would call high gloss but close.
He said he had started asking $500 at the beginning of the day, and mentioned he was down to $250 when I first started talking to him about it, 20 minutes later after poking around his other stuff and asking what else he had at home for 750 parts he said he had, he offered it to me at $200, so I pulled it out. I didn't even have to haggle with him. I spent 30-40 minutes talking to him and his dad reminiscing of rides and of a K0 750 his dad had bought new, did a few bolt on mods to and street and track raced against 900 Harleys and stomping them. It was a great visit meeting new friends. I'll have to ask him if he's the one that had a frame on Craigslist last year listed at $800....

Bryan
I asked him if he had gotten any stamps from the dealer in his parts purchase as he said he had gotten some tools....but no stamps....
I'll have to pick an old friend's brain that was a service manager to see what he remembers on the stamping they might have done.


Anyone have pictures of the K0-K1 seat latch frame bolt hole area to compare?
I've had some thoughts a few months ago of putting together a bitsa bike with a K0 duck tail seat and paint scheme.
« Last Edit: May 22, 2023, 03:17:28 AM by newday777 »
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 CycleRanger

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Re: Are there CB750 K1-K6 Frame Physical Differences??
« Reply #6 on: May 22, 2023, 05:53:48 AM »
That new frame is quite an amazing find! There certainly can't be many of those still out there.
Do you have a copy of the Honda Shop Manual or Parts List for your bike? Get one here:
https://www.honda4fun.com/materiale/documentazione-tecnica
CB750K5        '79 XL250s     CL350K3
CB750K3        '76 XS650      '76 CJ360T

Online newday777

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Re: Are there CB750 K1-K6 Frame Physical Differences??
« Reply #7 on: May 22, 2023, 05:58:22 AM »
That new frame is quite an amazing find! There certainly can't be many of those still out there.
Very true 👍
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 ZTatZAU

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Re: Are there CB750 K1-K6 Frame Physical Differences??
« Reply #8 on: May 22, 2023, 06:17:35 AM »
...Anyone have pictures of the K0-K1 seat latch frame bolt hole area to compare?
I've had some thoughts a few months ago of putting together a bitsa bike with a K0 duck tail seat and paint scheme.

Here's a pic of my 1971 K1 CB750 (mfg 12/70 s/n 1072xxx)



Hope this helps and it's nice to be able to start "paying it forward!"
ZT

Online newday777

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Re: Are there CB750 K1-K6 Frame Physical Differences??
« Reply #9 on: May 22, 2023, 06:27:46 AM »
...Anyone have pictures of the K0-K1 seat latch frame bolt hole area to compare?
I've had some thoughts a few months ago of putting together a bitsa bike with a K0 duck tail seat and paint scheme.

Here's a pic of my 1971 K1 CB750 (mfg 12/70 s/n 1072xxx)



Hope this helps and it's nice to be able to start "paying it forward!"
ZT
Thanks ZT. It should help.
Can you take a shot of where it bolts on the lower section of the latch?
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 ZTatZAU

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Re: Are there CB750 K1-K6 Frame Physical Differences??
« Reply #10 on: May 22, 2023, 06:58:48 AM »
Here you go, Stu!



Is this what you had in mind?
ZT

Offline C317414

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Re: Are there CB750 K1-K6 Frame Physical Differences??
« Reply #11 on: May 22, 2023, 07:02:57 AM »
What a great find!  Years ago my buddy bought the Triumph parts stock from a dealer that had sold Triumphs in the 60s and 70s.  As we were cataloging the parts, I found three sets of 750 engine cases with no numbers.  It was interesting,  because these were only sold on a one for one basis, to replace under warranty cases that were damaged.   Over the years he used two sets on personal projects and has one set left.

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Re: Are there CB750 K1-K6 Frame Physical Differences??
« Reply #12 on: May 22, 2023, 07:24:02 AM »
Here's the K2 & later, for those who don't have one. The "extra" ground wire on it comes from the mods I mention in my book about having old wiring: having an extra ground wire between here and the headlight will improve the headlight and instrument lights, and can make the turn signals blink again.
See SOHC4shop@gmail.com for info about the gadgets I make for these bikes.

The demons are repulsed when a man does good. Use that.
Blood is thicker than water, but motor oil is thicker yet...so, don't mess with my SOHC4, or I might have to hurt you.
Hondaman's creed: "Bikers are family. Treat them accordingly."

Link to Hondaman Ignition: http://forums.sohc4.net/index.php?topic=67543.0

Link to My CB750 Book: https://www.lulu.com/search?adult_audience_rating=00&page=1&pageSize=10&q=my+cb750+book

Link to website: www.SOHC4shop.com

Offline MauiK3

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Re: Are there CB750 K1-K6 Frame Physical Differences??
« Reply #13 on: May 22, 2023, 07:37:07 AM »
Way to haul a Honda with a Honda!
Great find.
1973 CB 750 K3
10/72 build Z1 Kawasaki

Online newday777

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Re: Are there CB750 K1-K6 Frame Physical Differences??
« Reply #14 on: May 22, 2023, 08:14:23 AM »
Here you go, Stu!



Is this what you had in mind?
ZT
Awesome 👌 thanks
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

Online newday777

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Re: Are there CB750 K1-K6 Frame Physical Differences??
« Reply #15 on: May 22, 2023, 08:17:48 AM »
What a great find!  Years ago my buddy bought the Triumph parts stock from a dealer that had sold Triumphs in the 60s and 70s.  As we were cataloging the parts, I found three sets of 750 engine cases with no numbers.  It was interesting,  because these were only sold on a one for one basis, to replace under warranty cases that were damaged.   Over the years he used two sets on personal projects and has one set left.
Cool.
I have a friend here that was a Seeley importers as well as the Norton dealer. He still has a bunch of Norton parts. I bought 2 sets of Morris Mags and 2 sets of Seeley Tickle reasets last year. I sold 1 set of each to a guy on Australia.
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

Online newday777

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Re: Are there CB750 K1-K6 Frame Physical Differences??
« Reply #16 on: May 22, 2023, 08:19:05 AM »
Here's the K2 & later, for those who don't have one. The "extra" ground wire on it comes from the mods I mention in my book about having old wiring: having an extra ground wire between here and the headlight will improve the headlight and instrument lights, and can make the turn signals blink again.
Thanks bro. It will help others I'm sure.
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 Lucien Harpress

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Re: Are there CB750 K1-K6 Frame Physical Differences??
« Reply #17 on: May 22, 2023, 03:43:13 PM »
I'm in the middle of a frame swap from a '75 to a '71 (even though the bike looked like a K2... mostly), and I can only add a couple of minor things.

1- The seat latch bolts for both frames were in the same location.  You can even fit K0 sidecovers to a bike with the later keyed seat latch, but the clearance is SUPER tight.  I switched to the earlier slide latch just because I could see myself scratching the sidecover at some point.

2- At some point, a small tab was added to the frame right above the rear brake pedal.  It has a bolt and a lock nut that rested on a small tab on the pedal itself, and gave you a bit of fine adjustment to the pedal position when it was at rest.  I noticed my '71 frame didn't have it.

3- No helmet lock hooks on the early frame, and my (admittedly Vietnam copy) K0 seat wouldn't even fit over them if they were there. 
-1970 CB750 K0
-1980 KZ1300
-1976 Yellow GL1000
-1965 CA77 "Dream"
-1997 Valkyrie
-1975 Velosolex

Offline HondaMan

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Re: Are there CB750 K1-K6 Frame Physical Differences??
« Reply #18 on: May 22, 2023, 06:56:33 PM »
I'm in the middle of a frame swap from a '75 to a '71 (even though the bike looked like a K2... mostly), and I can only add a couple of minor things.

1- The seat latch bolts for both frames were in the same location.  You can even fit K0 sidecovers to a bike with the later keyed seat latch, but the clearance is SUPER tight.  I switched to the earlier slide latch just because I could see myself scratching the sidecover at some point.

2- At some point, a small tab was added to the frame right above the rear brake pedal.  It has a bolt and a lock nut that rested on a small tab on the pedal itself, and gave you a bit of fine adjustment to the pedal position when it was at rest.  I noticed my '71 frame didn't have it.
Quote
Those little 'stop tabs' for the brake pedal first appeared on the New Factory K1 frames. Eventually they all had something like it.
Quote

3- No helmet lock hooks on the early frame, and my (admittedly Vietnam copy) K0 seat wouldn't even fit over them if they were there. 

Yep, the later seats were wider at the rear and narrower at the front. It helps with the shorter-legged riders to hold the bike up at stoplights and makes her feel more comfy on the longer rides. ;)

In your frame swap: if the upper rear engine bolt won't go into the triangle bracket on the right side, you might find that opening up the front right engine mount plate hole (the one at the engine side) a little bit will help fit it better (about 0.5mm to 1.0mm bigger hole there). Be sure to put the battery's ground lug in between the engine and the frame on the top left rear, too, and not on the outside of the frame there.
See SOHC4shop@gmail.com for info about the gadgets I make for these bikes.

The demons are repulsed when a man does good. Use that.
Blood is thicker than water, but motor oil is thicker yet...so, don't mess with my SOHC4, or I might have to hurt you.
Hondaman's creed: "Bikers are family. Treat them accordingly."

Link to Hondaman Ignition: http://forums.sohc4.net/index.php?topic=67543.0

Link to My CB750 Book: https://www.lulu.com/search?adult_audience_rating=00&page=1&pageSize=10&q=my+cb750+book

Link to website: www.SOHC4shop.com

Offline 69cb750

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Re: Are there CB750 K1-K6 Frame Physical Differences??
« Reply #19 on: May 23, 2023, 05:34:47 AM »

Quote
2- At some point, a small tab was added to the frame right above the rear brake pedal.  It has a bolt and a lock nut that rested on a small tab on the pedal itself, and gave you a bit of fine adjustment to the pedal position when it was at rest.  I noticed my '71 frame didn't have it.
Brake pedal stop was added in 72

Quote
3- No helmet lock hooks on the early frame, and my (admittedly Vietnam copy) K0 seat wouldn't even fit over them if they were there.
Helmet hook was added in 72

Online newday777

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Re: Are there CB750 K1-K6 Frame Physical Differences??
« Reply #20 on: May 23, 2023, 05:54:01 AM »

Quote
2- At some point, a small tab was added to the frame right above the rear brake pedal.  It has a bolt and a lock nut that rested on a small tab on the pedal itself, and gave you a bit of fine adjustment to the pedal position when it was at rest.  I noticed my '71 frame didn't have it.
Brake pedal stop was added in 72

Quote
3- No helmet lock hooks on the early frame, and my (admittedly Vietnam copy) K0 seat wouldn't even fit over them if they were there.
Helmet hook was added in 72
Thanks 😊
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 BenelliSEI

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Re: Are there CB750 K1-K6 Frame Physical Differences??
« Reply #21 on: May 23, 2023, 06:01:21 AM »
Stu….. what a unique find! Very cool!

Online newday777

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Re: Are there CB750 K1-K6 Frame Physical Differences??
« Reply #22 on: May 23, 2023, 06:04:07 AM »
Stu….. what a unique find! Very cool!
Yes it is John.
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: Are there CB750 K1-K6 Frame Physical Differences??
« Reply #23 on: May 23, 2023, 08:37:25 AM »
  I also have a k2 with a replacement frame. Its owner was a guy we knew for years, he didn't mention the frame replacement when my brother bought the bike. I have two unstamped engines also, they could combine to make a real enigma.
  I haven't found stamps that match the Honda font. A friend has Harley stamps but I haven't looked at them yet. The open top 4 is a tough one, as is the 9 and the segmented 0.
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 CycleRanger

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Re: Are there CB750 K1-K6 Frame Physical Differences??
« Reply #24 on: May 23, 2023, 11:27:48 AM »
  I also have a k2 with a replacement frame. Its owner was a guy we knew for years, he didn't mention the frame replacement when my brother bought the bike. I have two unstamped engines also, they could combine to make a real enigma.
  I haven't found stamps that match the Honda font. A friend has Harley stamps but I haven't looked at them yet. The open top 4 is a tough one, as is the 9 and the segmented 0.

I have a K3 with a replacement frame.
The PO was a little vague about why it was replaced, he said it was backed into by a road grader but he had no explanation as to why the vin was changed.
It is stamped with a completely non-Honda number that fortunately matches the title.


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