CB350 1971 Restoration Project

[AshimotoK0]

If you would paint a candy red over white you would have to add so many layers to cover the white that the colour would become very dark.
But even still.... it is called light ruby red. Not light candy ruby red.

Last week we stripped a nasty rust patch off Ben's tank. Definitely original paint  but multi layers from the factory just like  AndrewS's 750K1 tank. If it was a solid colour why wold Honda bother doing that? As per the Honda Bulletin, I am sill convinced it's Candy coat over white base coat. We are going to try a patch, as I have some Candy Ruby Red paint left over.


[ Guests cannot view attachments ]

[AshimotoK0]

Yeah there’s no life left in that bore anyway.

I think by looking at it I would probably get away with 0.50, I might keep going with the cleaning up and measure it once the pitting is out to see what the size is, suppose that’ll tell me what piston size I will have to go with then, or could go with 0.75 to be sure.

Don't do that Ben ... let Trigger look at it and assess it as it is.

[Bryanj]

Other thing is if you keep going and oval it its a swine to centraise on the boring bar

[florence]

I would agree with that, take it to someone who knows what they are doing.  I was told by Steve at Piston Broke in Bristol that Honda tolerences were really tight and he correctly rebored my 500/4, very close indeed.  He warned me I would have to run in very carefully but that there is no point in taking out more metal than is needed and that it would last longer as a result.  I followed his instructions and 26 years later it is still going strong.

If the pitting is really deep there are other pistons that fit CB350k such as Kawasaki GPZ750 (66mm).  Same crown and gudgeon pin size and valve cutaways fit perfectly.

[McCabe-Thiele (Ted)]

You would be surprised at how much metal you can remove with a stone I overdid it once on an A series engine.

Let someone familiar with the genre look at it - you can get your block courrier collected  & returned by Trigger they do an excellent service.

[AshimotoK0]

Ben took it to Trigger and he has  re-bored it and supplied oversize piston kits 

[BenPowell]

Hi everyone,

Not given much of an update for a while, in all honesty I haven’t been doing as much as I would have liked, generally life getting in the way.

Although I have finished building my shed, meaning I have some space to work on the bike through winter and I’ve started going through all the parts which have been boxed up for some time. Found some tools I forgot I even had as well 

Think the next step is removing the forks and wheels and start prepping the frame for paint, still not sure which route to go down with the paint, fortunately the frame looks to be generally rust free apart from the light surface rust in a few places.

I recently treated my car with Dinitrol and have some left over, don’t know if it would be worth doing the insides of the frame tubes with it to protect/seal it.

Hopefully will follow with more progress soon 

Thanks again

[BenPowell]

If you would paint a candy red over white you would have to add so many layers to cover the white that the colour would become very dark.
But even still.... it is called light ruby red. Not light candy ruby red.

Last week we stripped a nasty rust patch off Ben's tank. Definitely original paint  but multi layers from the factory just like  AndrewS's 750K1 tank. If it was a solid colour why wold Honda bother doing that? As per the Honda Bulletin, I am sill convinced it's Candy coat over white base coat. We are going to try a patch, as I have some Candy Ruby Red paint left over.


(Attachment Link)

Bringing up the paint colour topic again with an update, myself and Ash finally got round to trying out the candy red on the white base on a small section of the tank.
We sanded back the red top coat to reveal the white base below, we then applied the candy red over the white.
The image shows the colour achieved by just having a quick go with the paint, it seems to match the original paint very well. The front lower portion of the tank is the original untouched paint, the stripe of red running over the top is the sample. What’s interesting is to look at the bike originally I wouldn’t have thought about it being a candy red over a white base. Based on the sample today, the multiple layers of red/white paint and the Honda bulletin, I’d be confident in saying that it is the correct way to produce the light ruby red colour.
[ Guests cannot view attachments ]

[AshimotoK0]

Bit difficult from that image to see what is going on Ben.. I took this sample from your image though.

Interestingly my mate in Beverley had his 400/4 tank painted in 'Light Ruby Red' .. a solid colour supplied by RS Bikepaints. That red finish is typical of a 'solid colour' and nothing like your tanks original paint finish appearance.

Your tank's original factory paint finish is a bit like trying to describe/photo  the  CB750K0 Blue/green metallic .. you only see it's beauty 'in the flesh' and  photographs never do it justice.

I reckon if you use the candy ruby red, over the CB350 white as base-coat., as described in the Honda bulletin ... then  your bike is going to look absolutely stunning.  Given that your tank is original you can see that Honda (or their sub-contractor) had difficulty applying that paint combination as there are several failed attempts carried out on it prior to the final finish coats. Just like AndrewS's CB750K1 'Candy Ruby Red' tank.

[ Guests cannot view attachments ]

[BenPowell]

Hi everyone,

Had a rare bit of free time today and got the rest of the components off the frame, so finally I have a bare frame and parts which I can start getting ready for painting. I have a question though, when I tipped the frame upside down to remove the footrest bracket I noticed a puddle of water which came out of the head tube/steering tube. Thought it was a bit odd I’ve had the bike about a year now and it has been stored indoors since I bought it. Condensation maybe?

Has anyone else had this and would it be worth adding some drain holes near the bottom of the frame? I don’t like the thought of water being able to get trapped in there.

I was thinking about using some dinitrol cavity wax/rust converter on the frame, and I think I definitely will now.

Cheers

[AshimotoK0]

CB250/350K notorious for rotting out bottom front frame tubes particularly when the bike is left with the seat off or open in the rain.

Bring it into work on Tuesday and I can probe it in the areas that I know that they are prone to rotting out.

Yes some sort of wax protection and drain holes are not a bad idea although most classics these days rarely see rain but I know you are going to ride yours 

[BenPowell]

Hi everyone,

Been a few weeks since I’ve posted an update on the restoration, I got the frame and a few other parts back from painting and it gave me a bit of a needed kick to get on with the bike.

Forks have been stripped, cleaned and rebuilt with news seals and some fresh oil, actually feels like they have some damping effect now so that’s good
Rear shocks were beyond repair, although from the surface they looked good, it turned out the seals were weeping and one of them had a broken plastic sleeve, anyway got a new shiny set now.

One job I really enjoyed doing was lacing up the front wheel, I’ve been putting it off because it’s something I’ve never done, but I watched some videos and had a go and it went really well. Just need to true it up at work on Tuesday, although I had a quick spin and it really isn’t back at all.

One thing I need to ask is what everyone does about buying hex bolts, nuts, washers etc, every time I look there’s always a min quantity of say 50 or 100, is there an online pick and mix type or at least one anyone has used in the past for smaller quantities?

I’ll put some pics below of the progress

Next job, getting engine parts ready for paint

Thanks

[taysidedragon]

Frame and parts looking good.
Lots of places to buy fasteners in the sizes and quantities you want. I can recommend Stigs Stainless or Westfield Fasteners

[BenPowell]

Hi everyone,

Thought it’s about time for another update, I’ve had a productive few weeks and since been back on my 125 which I bought new when I was 17 I’m itching to get on with the CB350 project.

I know this topic has been discussed on here before but i was really having some difficulty in picking a colour to paint the engine, anyway I ended up trying about 5 maybe more different brands and methods before finally settling on one which I preferred which was the Dupli Color DE1615 and surprisingly a close second choice to that was the Halfords aluminium engine enamel. I also tried simoniz, auto tek and rust oleum but for me it didn’t look right. Some images below of the painted engine.

For anyone interested in the Dupli-Color I did two light coats followed by a third medium, painted in a warm room with 10 minutes between coats. Then once touch dry approx 1 hour I baked in the oven at 100 degrees C for 1 hour. (Not my kitchen oven though  )

Next topic, cam shaft & bearings. I was going through my parts checking for obvious signs of wear and my camshaft was looking a bit rough, some scoring/pitting and heavy wear on a couple of rockers, luckily I managed to find a NOS cam shaft but I need to either replace or modify the bearings since the one I have is past it. Think the bike might have been low on oil for a bit 
 I’ve heard about the roller bearing mod but has anyone ever bored out and re fitted a brass/bronze bearing into the aluminium housing? I’ve got the equipment to do it at work but I haven’t yet looked at what the clearances should be or if that information is available.

Hopefully I should be getting the engine together soon and getting it back in the frame, which will be a big milestone.

Cheers,

[florence]

My CB250K had phosphor bronze bushes put in as a modification.  I replaced them in 1985 with standard ones as they had worn out.  I don't know how long they had been in there as they had been done by the previous owner but they looked like a good bit of work.  I still have them somewhere, will try to dig them out.