Differences betweenCB750K & CB750F1

[AndyL]

After years of being a Yam' RDLC fan I'm now very much a CB750 Newbie, so here's my question:
Is there any difference between the frame of a 750K series bike (eg K2) and that of an 750F1 frame (I know the F1 has a rear disc) and what differences are between the two engines? Thanks.

[JonnyB]

Hi Andy,

I'm an old Elsie, fan, been tring to get a non runner for ages, but have you seen the prices. I had one of the first LC's not one of the ypvs jobs.

Oh SOHCs, I think the main differences between the K's anf F's are cosmetic,

There are difference between the F1 and F2 frame and wheels etc, the F2 has bigger exhaust valve making the head different.

Most of the engine differences are with the head and the carbs may be jetted different.

[AndyL]

Hi JonnyB,
Thanks for the info'. Yup, LC prices have gone up. I have an A reg RD350YPVS in red and white colours with the Bikini fairing, it's a complete bike but in need of total restoration. I had one of these the first time round in 1984 - fantastic bike. If your looking for a Yam' RD checkout the forum on Yamaha-rd.com, there's always project bikes / parts offered for sale before going onto eBay. You never know........

Anyway, nearly forgot it's a 750/4 forum. I have an idea to build a replica CR750. As I'm having difficulty locating a K project bike and I don't want to break up a complete bike I am thinking about buying an early F series bike, hence my original question. It will be a bike for the track only and I have the intention to parade it at CRMC events, for example.

I would be / am a novice track rider and am more interested in replicating the look of a CR750 than actual power of a CR750. That's why I'd like to know if the frame geometry, eg, steering head angle, is the same and does the engine looks the same?

I would hate to build a bike and then have someone point out that it's based upon the later F series bike.

[jimshea]

Andy,
An F1 would look very similar engine wise, but of course it was a 4 into 1 originally, so you would need new down pipes and finding the 4 into 4 silencers is not easy! I think the F frame may be longer than the K?
The F1 engine looks wise is almost identical I think? The F2 is black nad a bit of a handgrenade!
Depending on how much you want to spend I know someone who has  a K that would do, maybe it's a bit too good to turn into a CR750.
Where are you in the UK?
Jim.

Post edited by: jimshea, at: 2006/10/27 15:53

[AndyL]

Hi Jim,
Thanks for the response, I live in Churchdown, Gloucester. The exhausts wouldn't bother me as I would intend to put on replica CR750 pipes. Can you let me know if the person would be willing to sell his K series bike. If it's a semi-project bike then Ok i'm interested, But I don't really want to break up a good-looker - there aren't to many of these bikes around now.

[AndyL]

Hi all,
I think I've answered my own question - In the photo groups there is a photo (number 16 of 33) that shows the bike I'm looking at building / replicating - and it's based upon an F1.
Jim, You have made a comment on this bike aswell. I would be interested in the bike that you know might be for sale - and seeing the photo I've had a slight change of plan as I would keep it road legal aswell, just like photo 16.
Let me know if it's for sale. thanks, AndyL

[jimshea]

Andy,
I will check if the bike is for sale, it is MOTd at present so is a decent bike.
Jim.

[SteveD CB500K0]

AndyL wrote:

Hi all,
I think I've answered my own question - In the photo groups there is a photo (number 16 of 33) that shows the bike I'm looking at building / replicating - and it's based upon an F1.

Andy - that bike belongs to Mark Magenis in Chelmsford. He had it for sale the other day (