Topic: Questions about the 71 K1 I just purchased

[David B]

Hello all,

I finally squeezed the trigger last weekend on a CB 750 and picked up a k1.  The bike is in pretty good shape and complete with what I think are a few swapped parts.  Specifically, the gauges do not have the warning lights incorporated into them (they're on the handle bar) and the fork ears are chrome with the turn signals in the wrong location for a 71.  The date of manufacture is 9/70.

First question: Any chance the gauges came that way from the factory?  I haven't done any investigation yet to see if the wiring harness is hacked up.

Is there a simple reason why someone would switch out the fork ears for chrome ones or is that one of those questions that could have a million answers.

I'll post some pics soon, thanks for your help guys!

David B

[MCRider]

That's a shame. K1 instruments are about the most elusive. They have the idiot lights on the face like a K0 but have the lens of a K2. Only ones like them, bring BIG money on eBay.

Sounds like you have a K2 front end. But only time and research will tell.  Could be result of an accident. PO didn't want to replace broken K1 gauges as Too $$$, so bot a used k2 front end.

[David B]

Yeah, it's a little disheartening to find out the bike isn't original.  I simply didn't know how the K1 was different with regard to the gauges, headlight ears being painted, location of turn signals, etc.  My fault for not knowing more than I did.  I still like the bike a great deal though and will find the right gauges & head light ears before repainting it one of the correct colors.  The seller had added the grab bar for convenience, I don't think it's correct for this year either but it's gonna stay for convenience. 

Another question:  Are the K1 and K2 head light ears the same other than the chroming on the K2?

Thanks for all the help guys, I sincerely appreciate it.

[David B]

Here are a few pics:

[MrGardman]

There are a few more things that might be questionable. The side covers are different (later I think). Also it has the larger chrome tail light mounting bracket. I also noticed the little splash guard for the front rotor.

Maybe someone else could chime it cuz I am not sure, but could this be a K2 bike instead? I know going by the production date this should be a K1.

Still though a very nice looking bike and you should be proud to own it.

[Viktor.J]

The seat should also be a K2, the color is repainted as far as I understood

[Johnie]

Welcome to the board - Regarding your question on the fork ears, yes there is a difference in the K1 to the K2. They are shaped a bit different. Below is a pic of the K1 ear for you to compare. I am sure you are aware that is a new paint job on there. The tank stripe is a bit wider than original. Don't get me wrong, that is a really nice bike and the board is trying to help you identify what you have there. Did you get a title? Check to be sure your title matches the bike ID. It could be titled by the engine number or by the number on the steering neck. Sure looks like a K2 to me also. Even the handle bars look taller for a K1. I will include a pic of the K1 gauges to educate you on the difference. My first thought was you had a K2 built in fall of 1971. But the build date of 9/70 would not jive with that theory. Click the pics to enlarge.

[fire113]

Hi David

...the complete fork isn't K1 include the gauges(<-K6 I think) and the upper fork bridge , side covers are the same (K1-K6) only the "750four" sign is wrong, the lamp housing should be painted.

Have a good one...Georg

[ekpent]

Do you have the extra button down on the bottom of left  hand grip control? Looks like a starter button hanging down there. It was a 72 only deal and was a turn signal buzzer shut off button.If you have that you have a 72 which is what it looks like to me,painted K1 green. Is the chain guard plastic or metal,plastic K1,metal K2 or later     Post up your frame and engine numbers also for fun for verification.   Also are the exhaust pipes HM300 or 341 ?

[Dream750]

Another question:  Are the K1 and K2 head light ears the same other than the chroming on the K2?

No, the chrome K2 head light ears have an additional bracket (see pics) for the K2 turn signal buzzer assembly.

Welcome to the forums. 

[ekpent]

His chrome fork ears look to be 73 or later with those turn signal mounts.

[Viktor.J]

In europe I belive we had the same mount for K2 also..not 100%

[Stev-o]

Welcome David.  Unless you paid $7K for an original K1, none of this should surprise or discourage you.  Yes, there could be many reasons why parts were changed out includng "upgrading" to chrome fork ears at some point.  Many of us have bought bikes that were "butchered", yours is still a very nice bike.  It could always be brought back to original, just takes time and money. 

[CrankyOldGuy]

Please tell us what the engine serial number is ... this may shed some light on the issue.

Also,  back in ancient times (1971) you have to remember that this was the time of chrome.  Many of us had the fork ears chromed and I also had my headlight bucket painted black ... we thought there was too much red and not enough contrast.  Amazingly the K2 came out the next year with chrome fork ears.  Now I am repainting my fork ears and headlight bucket back to candy ruby red .. imagine that 

Harry O.

[David B]

Thanks for all the help guys! The vin is 1054603.   Here are a few more pics:

[Stev-o]

The signal cancel button is on the LH control.

[David B]

Also, the pipes are 341s

[David B]

The engine number is CB750E-2396620 which, if my quick research is correct, is out of a K5??  Looks like the only thing that's a K1 on this bike is the frame, right?

[Stev-o]

Def not a K2

[cbr954]

Yeah looks like K5 motor and K1 frame by the numbers

[Tews19]

Welcome to the site! Nice 750 you have there. Don't be discouraged finding out its not 100% original unless that's what te PO told you. What are your plans for it? In regard to the pipes being 341s. Not a big deal. They look great. Johnie posted pics of the k1 tach and speedo. If you look in the for sale thread you will see a nice faced one with a small ding for a decent price. Enjoy the bike as is or restore an welcome to the SOHC community!

[David B]

Maybe there's really no  point spending a pile of money to turn it into a more complete K1 if the engine's a K5.....  Just thinking..... 

[Tews19]

K1 engines are out there.

[fire113]

The engine number is CB750E-2396620 which, if my quick research is correct, is out of a K5??  Looks like the only thing that's a K1 on this bike is the frame, right?

Hi David,

...but the head is not looking like K5, looking like a K2 may be K3 not sure when Honda changed them but I think it was after the K3.
Fork and break swing arm and the little fender for the break disk is >= K3
Not sure about the front fender, the break line holder <= K2 was not welded on the fender.


Good luck...Georg

[Don R]

Back in the 70's and later is was considered cool to swap to later parts. Made your bike look newer. Sometimes a bike was layed down and it was way cheaper to buy a parts bike and just swap parts over. My brother was buying them all around here, making one nice bike from several beaters.