Topic: 1969 Diecast/ K0 restoration

[UK Pete]

Hi all i was posting this thread on another site but it seemed to lack any interest ,but i am sure you guys will enjoy it so i will copy you in on it
 I have been thinking as to which way i shall proceed with my K0 at first i was going to get it MOT'd register it and ride it as is for a year or so while i have a chance to gather parts to restore, but on closer inspection i have found the front end needs a total overhaul, so does the back end (swing arm bushes, missing spoke in rear wheel), and even worse the engine leaks oil from the cylinder head quite badly, so it is pretty much decided that i will tear it down and get stuck in with a restoration now rather than later, To kick things off i got the bike running , just needed a bit of work on the carbs, then rode the bike around to get the feel what was in need of doing, that is when it became apparent that both front and rear ends were bad, and it was clear the oil leak was more than just a drip, i cleaned up any chrome bits to access what was salvagable and what was to replace, it tuns out the double cut front guard is really solid with speckles of rust and a couple of small dings that are easily repaired, so that is on the re-chrome list








The rear guard is also in reasonable shape, and being the original well worth salvaging so that is also on the re-chrome list, again like the front it has a bit of mild surface rust , and a few dents, but the dents are where the rear light has been knocked and so are mostly hidden, the underside has been protected with some sort of wax oil and is really well preserved, as for the rear light bracket i have A NOS bracket, and chrome rear light back, the original lens is salvageble with a bit of polishing so all is good

[UK Pete]

More pictures of the strip down

Short plastic chain guard, it is all there, in dirty but good condition, luckily as reproduction ones are almost £200
originals very hard to come by


Front brake all in good condition, just a bit of fading to the anodised parts


the original no 8 bolts in great condition, they will clean up nicely so a few less to zinc plate


Coils looking a bit worse for wear but considering the bike ticked over like a swiss watch at only  800 rpm, and reved cleanly from there upwards means to me they are worth keeping and restoring




Original airbox, looks to be repairable , although i do have a nice new LPM one which i might use




More of those lovely no 8 bolts, i think they were only on the pre K1 models




Rear indicators and mountings , amazing condition, perfectly usable, just need to paint the brackets


Carbs with the 4 seperate cables, apparently a bit awkward to set up properly,, but all there and working good


Surprisingly all the electrics worked faultlessly, but i will have my work cut out restoring this lot



Swing arm a bit of rust , but structuraly sound


Swing arm bearings are metal in this one, and were a real pig to get out


Front forks , need total overhaul, the chrome is good , but strangely Honda chose to only chrome the area of travel, the rest is bare steel so it goes rusty


Fork internals, had a right job getting one of the retaining circlips out, also they had a mix of water and very smelly discoloured oil in them


Engine out, i opted for the easy way lay the frame on its side and remove bolts and lift away from engine,
the engine is bit oily but it ran really sweet with no smoke, all the fins are in tact, but it leaks oil from the head quite badly, this will have a total strip paint and be fully reconditioned


Frame had some  rust but mostly surface, just a couple of pin holes in lower tube, which i enlarged out till i was back into sound metal, then i welded them shut and ground it down and sanded smooth

[ekpent]

For fun do you have a picture to post of the bike before the teardown ?

[UK Pete]

I will find a picture and post it soon but for now here is some more

I was wondering how to get out my stubborn swing arm shock bushes, then i came up with the old socket trick and threaded bar, a bit of heat from a gas torch and wind up the nut they just pushed out,



 shame the steering head bearings wern't as  easy, turns out who ever put them in had done it with the bearing seat at an angle and so they were sort of friction welded in, i got them out eventually but will have to file the chived up metal back smooth again

[Viktor.J]

Nice work there pete, are the plan to restore it to full original condition ? colour ?

[MrGardman]

Looks like a fun project with the big pieces intact. Good way to start.

[UK Pete]

Its a great project, and i am really enjoying it, although it is going to cost some serious money to get it right
As for the colour i have always fancied the candy blue/green, but the original colour was candy ruby red so i have a hard decision to make, i already have a candy ruby red k1 sitting in my garage so the green blue is looking like favourite at moment

[UK Pete]

Thought i would do a bit of work on the front end, i am not sure what people do with their forks ie replace them cause they are rusty at the top, or just treat the rust and re use, i decided to reuse my fork stauntions as the chrome on the travel part of fork is perfect, the top part which honda left as exposed steel is not seen and the cost of replacing the tubes just because of unseen rust is not worth it as it would just add another £200+ pounds to the restoration cost for me to know that hidden behind the fork ears is shiney chrome
what i did was rub them down, treat with a chemical rust convertor, then a fine coat of silver paint







I stripped the top yolk of its paint and gave it a couple of coats of satin black, the finish is almost spot on to the original, i know as i have a NOS one to compare to












While i was in the mood i removed the steering lock and bearing  stripped and re-painted the lower clamp, but used gloss black as that is what was used originally

[Maksimum Hops]

I'm glad you posted almost a step by step of the forks! That's a pretty good reference, thanks.

[markb]

The steering stem and fork top turned out great.  Nice attention to detail on the "color" difference between the two parts.

[Garystratos201]

Very nice project. It looks like you have a good bike to start with so it will be a little cheaper than it could be. I was amazed at how fast the cost added up on my K1 project. I`ll follow your build with great interest.............Gary

[UK Pete]

Trouble is with restorations is to get a reasonable standard you end up renewing or reconditioning most of the parts regardless of condition anyway, luckily i have most of the hard to find bits so that will keep the cost down, but saying that i payed a lot for it in the first place because it had these parts, speaking of which here is the tank

My tank was looking very tatty and i was unsure to its condition beolow all the horrible black paint, so i just had to strip the paint off to access the state of the metal, to my surprise it is in fantastic condition there is only one dent and virtually no rust inside and out , plus the added bonus that it is the original correct tank for the year , just look at those lovely wrinkles and the original cap

Getting the mucky old paint off, the original colour was candy ruby red


Lovelly deep ridge wrinkles




No rust inside


Starting to reveal the beutifully preserved metal on this 43 year old tank


I am so pleased with this , i spent a lot of money buying this bike but having most of the original parts is sometimes priceless


Only one dent, does anyone have any suggestions on how to get this dent out?

[UK Pete]

Here goes then time to strip the engine

Rocker cover off,a well preserved number written on inside




 all looks good in there



Cam towers off they both have a code on the side, could it be a date ?



I have had one of these snap before so i am not taking any chances as this one is in real tight, a bit of heat and a hit from the hammer free,s it up



Off with the head,it has had a serious oil leak for some time by the looks of it




Off with the barrels




Open up the crankcase, all looks good, vitually no sludge, just a few bit of muck in the oil strainer




Washed the cases in my parts washer, more preserved numbers written inside







Could this be the bearing code on the underside of front upper crankcase





At last some sort of order, all small bits baged and labled, cases cylinders and head all washed clean , now i can work my way through this lot and see what i need to order

[Greggo]

I just had a couple dents like you've got in the tank removed by a paintless-dent removal guy.  The before-and-after was astonishing, and it only cost $40.

Great progress so far!

[Dream750]

UK Pete, I’ll be following your project bike thread as originality restorations are my favorite. And looks like your off to a great start, especially with the photo documentation and attention to detail.
 
Is your bike a UK or USA model?

[UK Pete]

Greggo , thats a good idea i will look in to it and see what can be done
Dream750, i am definitely going for original as much as my budget and practibility can afford,  i intend to photo this every step of the way as i think it makes things more interesting, as well as there will be good reference for others, i will try and keep attention to detail as i have a vision on how i want my bike to look , 
Pete

[Prospect]

Yes, that is the bearing code.  You'll need to match those to the ones on the crankshaft to figure out which colour bearings you need. 

[UK Pete]

The engine sounded sweet before i took it apart, the crank bearing surfaces are  good  and the shells show little sign of wear, so i have numbered them in a way that i can just put the old ones back in
I dont  think its worth replacing them , but i would be interested to know what A- B code is in relation to the colours
Pete

[markb]

This link will provide some information:
http://data.sohc4.net/SB750/750_14.pdf
It should also be in the shop manual.  You can down load it here:
http://forums.sohc4.net/index.php?topic=17788.0
Good luck.

[Prospect]

The engine sounded sweet before i took it apart, the crank bearing surfaces are  good  and the shells show little sign of wear, so i have numbered them in a way that i can just put the old ones back in
I dont  think its worth replacing them , but i would be interested to know what A- B code is in relation to the colours
Pete

You might not have to replace them but the only way of knowing is to measure.  One way is a plastigauge test as described by the above service bulletin that Mark posted. Easy and much cheaper than blindly replacing  bearings.

[UK Pete]

Thanks for the links to the info mark
Prospect, your right there is only one way to be sure and that is to measure, when i rebuilt my F2 engine, i done a visual check on the crank main bearings and was happy that the smooth unridged surfaces,  was good enough for the old shells to go back in, so thats what i did and it is sweet as a nut, with the big end bearings i left the conrods untouched as they felt perfect, i have to say i have built many different engines over the years and i am happy that i can make these accessments and so far have never made a bad call, but for this k0 engine i think i will do it all by the book
Thanks guys
pete

[UK Pete]

Done my battery box and electrics this weekend, a bit random i know, one minute i am doing the tank then engine, the next i am doing this but i suppose it pays to do anything  as it is all a step nearer to the end

Here is a reminder of the battery box and electrics






Zinc plating some of the bolts and brakets








Lots of other bit done , bring it all together and it looks real good i think,

[Missingparts]

Awesome work! The zinc plating looks great.  I'm planning on giving plating a try myself.

[Prospect]

Excellent work with the zinc plating.  I'll have to try that as well. 

[iron_worker]

Did you zinc plate over the old zinc or did you strip it with some kind of acid? What sort of surface prep did you do? I just got my heater for my zinc plating kit so hopefully I can start on my plating adventures soon too.

IW