Honda-SOHC
SOHC.co.uk Forums => CB750 => Topic started by: Lobo on November 29, 2021, 12:03:32 PM
-
I really appreciate my 1973 K2, ride / use it a fair bit, and am definitely not overly precious about it….
As an early NY project I’m planning to treat it to a facelift, and have the body set repainted (in touch with Menno right now), the engine out / fettle an occasional jumping 4th gear, engine repainted, cases polished, carbs vapour blasted etc. Most of the work, as a recent retiree (yay) I plan to try myself, whilst learning a bit along the way.
All good, until mentioning this to a K1 mate today. In the past he’s noticed my motor is actually a K3 lump, and highly recommend I seek out a replacement case with an Eng # plausibility in line with the K2 frame #.
Now I’ve been visiting the Sandcast forums lately, and from here too, realise that these folk and the K1 types (!) can be a bit ‘sniffy’ about what they’ve got (😂) - which is understandable given the changes the ‘750 was going through in 69/70. But by the time the K2’s + came along, I’d have thought the bike was considered in serious mass production, and ‘matching’ numbers less of an issue - particularly wrt resale value etc.
So… my question is… should I bother with this advice? Honestly my engine is a good ‘un, pulls strongly, has never missed a beat … or burned a drop of oil. I don’t plan a massive outlay of $$$s on this recon (since doing much of it myself), but swapping the Eng #, I could see, might be a pain & a path I wish I hadn’t bothered with.
Thoughts?
Ta.
-
Don't bother
Sent from my SM-A750FN using Tapatalk
-
I agree not worth it, it will never be a megga money bike
-
Just ride it, it makes you smile. Let em sniff ;)
-
Is yours a UK bike Simon? Your mate may be telling you it's a K3 engine when if it is a UK model, the engine number would be correct for a UK K2 seeing as we had K2's from 72-75.
-
Thanks all - appreciated.
Yep Julie, I believe the bike to be a UK model.
The numbers…
Chassis No. CB7502077106
Engine No. CB 75E2241656
There indeed seems to be a mismatch?
Ta,
Simon
-
Thanks all - appreciated.
Yep Julie, I believe the bike to be a UK model.
The numbers…
Chassis No. CB7502077106
Engine No. CB 75E2241656
There indeed seems to be a mismatch?
Ta,
Simon
Think that you will find that because the UK continued with the K2 model until the K6 arrived, that from around 72 to 75/6 all UK bikes would have had frame numbers in the 20******** range and as such the engine No's would have been in the 20********* for 72 but in 73 the engine No's would have changed to 22****** series in 74 23******* etc.
So you need to check what year the bike was first registered as you may well find that it has the correct engine and frame No's for a UK bike of that year.
-
Interesting Julie / Sprinta - I had never thought about this, my UK K2 was first registered in June 1973.
Is the general consensus then, that my mid ‘73 K2 has its original engine then?
Frame No. CB7502077106
Engine No.CB 75E2241656
Many thanks,
Simon
-
Thanks all - appreciated.
Yep Julie, I believe the bike to be a UK model.
The numbers…
Chassis No. CB7502077106
Engine No. CB 75E2241656
There indeed seems to be a mismatch?
Ta,
Simon
Think that you will find that because the UK continued with the K2 model until the K6 arrived, that from around 72 to 75/6 all UK bikes would have had frame numbers in the 20******** range and as such the engine No's would have been in the 20********* for 72 but in 73 the engine No's would have changed to 22****** series in 74 23******* etc.
So you need to check what year the bike was first registered as you may well find that it has the correct engine and frame No's for a UK bike of that year.
All UK CB750 K2's would of had frame/Vin numbers 20****** or in vary late 1974 and 1975 the frame/VIN numbers 21****** ;D
Yes Simon, By our records your UK K2 has matching numbers .
-
Wow, this forum is amazing.
Thanks Julie! (and indeed all…)
-
Your UK K2 would of had 300 type forks fitted.
Unicorn top yoke As, all UK K2's has unicorn's
Switch gear as per picture
And square pattern seat
[attachimg=1]
[attachimg=2]
[attachimg=3]
[attachimg=4]
-
I recognise that flooring
-
I recognise that flooring
😂 😂 😂 😂 It looks like it needs a bloody good srub as well Bryan but it's not too bad for a workshop.
-
Wow, all present & correct on the stipulations Julie…
My throttle has the ‘Cruise control’ friction screw on the underside too; don’t seem to remember it having it when I bought the bike, but there was the threaded hole ‘ready & waiting’. So, I found the correct part and presto, I can set a rpm for balancing etc.
Also I don’t have the P(ark) notation, but rather just a dot.
It looks like you’ve deleted that crap UK requirement switch on the LH side, basically powering the headlamp ON (as I recall) to avoid going from HI straight to OFF position.
Interestingly your kill button is set at 90 degs to mine… !
-
Your switch is a later one from a 400/4 or 550F.
The original UK K2 switch is part number 35300-300-730. Also fitted to the UK CB500 Four K1.
[attachimg=1]
-
Head Up Display clocks in the seventies too?...
-
Think that you will find that because the UK continued with the K2 model until the K6 arrived, that from around 72 to 75/6 all UK bikes would have had frame numbers in the 20******** range and as such the engine No's would have been in the 20********* for 72 but in 73 the engine No's would have changed to 22****** series in 74 23******* etc.
So you need to check what year the bike was first registered as you may well find that it has the correct engine and frame No's for a UK bike of that year.
I'm picking up on this just now, after a long absence, because I have the same thing: Frame - 208**** and engine - 231****
When I started my rebuild I used a K2 parts book, out of ignorance, but later realised I should have been using a K4 engine parts book, or should I?
Or should I use a K4 parts book for both frame and engine?
Cheers
-
UK K2 parts book taking note of changes by engine No
-
Thanks Brian
I'm happy now as that's, in fact, what I did. :)
Sean