Honda-SOHC

Always here for you Ken ..you know that mate. Just tell me the make if you know it without venturing outside of course.

Decided that I have too many CB250/350 projects. I am keeping my '68 CB250K0 (Candy Red), My '70 UK CB250K2 (Candy Gold) and my '69 CB250K0 JDM version(toaster tank, combined clocks etc) !

I am parting out my ultra early VIN '68 CB250K0 (Sardine Blue/White ) and my Candy Blue/White  '69 CB350K1 (USA import from Wyoming 10K miles).
The 250K0 Sardine Blue paintwork set I did myself with RS Bikepaint and 2K lacquer with pro-spray guns ( DevilBiss) . it's a lovely Job ... even if I say so myself .. The tank was NOS in primer (Non-sanding as Honda put it ) . The 350K1 paintwork was done professionally in Candy Blue/white.

The 250K0 I  have  a really early V5 for (the frame No is in the 500's it's that early !)  The 350K1 I have the USA (Wyoming) Title.

The bikes are matching numbers. The engines are totally stripped but some really nice parts ( cam and followers are lovely for instance). The lovely condition '68 250K0 frame is in original paint and the 350K1 I had 'sympathetically' powder coated. Seat wise the 350K1 has an either NOS or dealer take off seat (a few minor marks but you would be hard pushed to find a better one... the seat is exactly the same as a CB250K2 model). The 250 K0 seat is in nice condition but may or may not require a new cover ..depending how fussy you are).

The mudguards for the UK model  250K0  (deeply valanced) were both re-chromed by Prestige and are near perfect (cost ££££'s) The 350K0 'fenders' are original and the chrome is lovely with no dents. I have decent carbs for both bikes, clocks,swinging arms, forks Yokes, wheels,  chainguards (NOS IIRC), centre /side stands (repainted), rear lamp assemblies  etc, etc.

Exhaust wise ... I have loads of genuine exhausts but I won't part with any until I have checked I am covered for the bikes I am keeping . I know I have a spare NOS early-one piece exhaust with one noticeable dent in it.... I scoured the globe for 5 years to find a pristine set of one- piece exhausts for my own '68 ... they really are that rare !
 
PM me if interested and I will send my WhatsApp number to show photos.

**********TECH OVERLOAD WARNING! ALERT FOR ODDJOB, ETC.  *********

I got my ultrasonic cleaner out of the skip at work and fixed it ...made by Ultrawave.
It worked great for a while then BANG ! popping all fuses. Managed to fix it but after a few months BANG ! again.
When I looked at the bank of output transistors they all had a number hand written on them. I found out that they matched all of the transistors at the factory and I don't have a clue how to do that. I don't think it's just a matter of gain matching... If you don't perfectly match them, then they don't share the current correctly and eventually go BANG! Problem is with the design of these things they are switching high voltages at high frequency into a highly capacitive load.

Ultrawave is similar design to this one.

[ Guests cannot view attachments ]




I do have another smaller one that is of the same era and that seems less fragile. Made by Decon Scientific. Pic is of 300B model but mine is a 400B so larger. Got given it as being 'BER... (Beyond Economic Repair).



[ Guests cannot view attachments ]

Firstly check you have the correct carbs as they often get fitted with earlier ones.They should be 725B. Spring wasn't available as a separate part ...it comes with the diaphragm / piston assembIy...I would probably assume it's OK unless someone has changed the diaphragm to a 350 one...as I think 350 diaphragms assemblies are different .... I will check on my parts books for you and reply again.

How do the part numbers compare to the ones shown in the 500 manual?

Not sure Ken .. will check.

A Serdi is a big industrial machine like a Bridgeport mill that can replace seats and recut the angles acuratly, not a home tool and only big machine shops have them.
I must admit to never seeing hand cutters in the dealers kit, may have been an early one, all the Honda seats are supposed to be Stellite which is why they say grind with stones.
I know Trigger found a full stone kit some years back and was happy to buy it, dont know if he sold it.

Those valves just look too rusty for me to trust them in everyday use, head comming off would totaly trash the motor

I know that 450 Bomber valves are Stellite faced Bryan..... But pretty sure that at least the early 750 valves  were solid and Trigger deffo refaced them for me with that full stone kit .. he did sell it to a member on here. My 750 toolkit has a separate little green box inside the main box with the cutter set in it. Still totally unused in my kit as Graham did my head refurb. It came from Alf Briggs's stuff (he was Honda's main service man in Nottingham and a very close friend on Mr Honda himself).

Interesting article on Alf here  : https://www.dropbox.com/scl/fi/5l31rcxe39ljobilv6d9k/Alf-Briggs-5.pdf?rlkey=rsg3natiqsqi752zi6w09grp2&st=v48vy2ns&dl=0

I agree that the head looks pretty knackered. I think my 500K0 had Mitsubishi manufactured exhaust valves. (were they Stellited)

Evidently the final price includes 10 % fees ...so indicates that someone present in the auction room bought it as telephone/net bidders pay 12%  ...not sure how correct this is someone on FB told me.