1970 Honda CB350K3

[julianl]

Another great thread unfolding here . I'm not going to read it all now , I'll save that pleasure for when I'm bored at work . Those carbs , salvaged from the Mary Rose by any chance ?

 

Thanks, and I guess that's a positive side of the holes in the float bowls - only one carb was in that bad condition.

[julianl]

Update 15 - July 2018

'New' fork covers off eBay (good condition second hand ones).

No dents in these ones!

Scuffed up the surface with wet and dry, then primered.

I didn't want the front end all the same colour, so I went with black for these.

I gave the tank a final light wet sand, getting ready to apply lacquer.

First coat of lacquer.

I used a petrol resistant lacquer.

Second coat of lacquer.

[Smithers]

Another great thread unfolding here . I'm not going to read it all now , I'll save that pleasure for when I'm bored at work . Those carbs , salvaged from the Mary Rose by any chance ?

 

Thanks, and I guess that's a positive side of the holes in the float bowls - only one carb was in that bad condition.

 

A classic case of petrol worm. Question; do you have your own sand blaster? A really interesting thread julianl.

[fastbob]

That brand of petrol proof lacquer . Have you used it before and is it any good ? How petrol proof is it ?

[julianl]

A classic case of petrol worm. Question; do you have your own sand blaster? A really interesting thread julianl.

 

Yeah, pretty much No I don't but I would really like one. I just don't have the space. I'd doing most of the work at a friends garage as there's barely room to stand in my garage. Thanks. Progress is slow at the moment, I didn't really do much over winter, but plan to get the bike on the road (hopefully) before the end of summer this year.

 

That brand of petrol proof lacquer . Have you used it before and is it any good ? How petrol proof is it ?

 

First time using it, and I haven't tested it yet, so hopefully the answer is 'enough'. With hindsight, I probably would have left the top of the filler neck bare metal, so I guess we'll see the first time I fill it up. It's certainly had long enough to dry and harden.

[fastbob]

A classic case of petrol worm. Question; do you have your own sand blaster? A really interesting thread julianl.

 

Yeah, pretty much No I don't but I would really like one. I just don't have the space. I'd doing most of the work at a friends garage as there's barely room to stand in my garage. Thanks. Progress is slow at the moment, I didn't really do much over winter, but plan to get the bike on the road (hopefully) before the end of summer this year.

 

That brand of petrol proof lacquer . Have you used it before and is it any good ? How petrol proof is it ?

 

First time using it, and I haven't tested it yet, so hopefully the answer is 'enough'. With hindsight, I probably would have left the top of the filler neck bare metal, so I guess we'll see the first time I fill it up. It's certainly had long enough to dry and harden.

 

A good coat of wax might be a wise move , great work. This reminds me a bit of my first ever bike , a CB 175 , same colour. I'll get that clock in the post tomorrow .

[julianl]

A good coat of wax might be a wise move , great work. This reminds me a bit of my first ever bike , a CB 175 , same colour. I'll get that clock in the post tomorrow .

 

Good idea with the wax, I will do that before I fill it up. Much appreciated, thank you

[julianl]

Update 16 - July 2018

Lots of carb work this update, but first, one more coat of petrol resistant lacquer on the tank. This is the third coat.

I got a second set of carbs, and a couple of rebuild kits. Hopefully I will have enough to build two working carbs.

Much better condition.

Disassembly and clean. The wooden dowl is for knocking the emulsion tubes out. Neither are threaded, but one end of the ide emulsion tube looks like it's slitted to accept a flat blade screw driver - this will just snap the end of the tube off, it needs to be pressed out.

Damaged butterfly, need to swap that with one of the others.

Rebuild kit from Japan (via CMSNL). I'm used to the price of rebuild kits for my CG125 engined XR125L or Kawasaki GPZ500S, so the price of these were unexpected.

Going back together.

New needle.

First carb almost rebuilt.

This is where I discovered I have two very similar but different carbs. Arse.

I only discovered the above, then I installed the new mixture screw spring and tried to install the mixture screw. The new screw wouldn't fit, and I couldn't fit the old one as it didn't fit the new spring, and... I couldn't get the new spring out as it was the wrong size spring for this carb.

It took me the best part of two hours to fish the newer and incorrect size spring out of the carb body. It was only when I had the new and old next to each other that I realised the difference. Lesson learnt.

Back to this one to harvest parts.

Back to the other good one and started to install the parts from the rebuild kit.

New float bowl (no holes).

Second carb back together, no holey float bowl, no damaged butterfly, and new carb rebuild parts installed (jets, etc)

Both carbs bagged up ready for reinstallation at a later stage of the rebuild. But.... I revisit the decision to mix two slightly different carb revisions at a later date.

[linuxrob]

Wonderful thread, another forgotten bike back to doing what it was built for. Great work

rob B

[julianl]

Wonderful thread, another forgotten bike back to doing what it was built for. Great work

 

Thank you, much appreciated!

[julianl]

Update 17 - July 2018

I wasn't happy that the two carbs had different idle screws. I'm sure it would have worked fine, but I would prefer them to be identical. I have a body that's the same as one of the good ones, but it's got a stuck float valve seat. I have a replacement seat, and the old one should just pop out, but it's stuck solid.

I get to the point where I've marred the brass so badly, that there's no option not to change it, so I just go to town on it with the pliers after soaking it with penetrating oil. I could see there was some scale build up around the seat, and assume that's what's holding it in there. I try to scrape as much of it off as I can, and spray a load more penetrating oil down there. After about an hour of messing with it, I get it out.

I decide to clean up the other carb whilst I'm at it.

The slide is jammed on this, so strip as much as I can off the carb body to get it to fit in my tiny ultrasonic cleaner.

Hmmm, I may need a bigger boat.

Perfect!

I did about 10 minutes on one side and then flipped the carb over and did another 10 on the other. After this, the slide came free.

You can see the varnish in the bore. Most of this wiped clean with some carb cleaner now I could get to it.

I start moving the new parts over from the 'slightly different carb' to the matching carb.

It was the idle mixture screw that was different.

They are now the same on both carbs.

Once I finished up on the carbs, I turned my attention to the tank.

I had bought a new 'lock' set for it, as well as cap. I was a little paranoid about scratching the tank, so used lots of painter's tape.

Installed.

Ignore the white marks around the tank badge, it's polishing compound. I started to polish the tank, and then thought better of it. Best let the lacquer cure longer and polish it just before I put it on the road.

Time to fit the 'chrome' stripe at the bottom of the tank.

Tape removed.

Same again on the other side.

I was initially looking to get the back back on the road pretty quickly, so didn't want to do a full restoration. That's why I didn't paint the yokes. I started to put it all back together.

That's where I ran into another problem. The top bolt in the forks goes through the top of the top yoke. The fork doesn't pass though the top yoke. The headlight bracket and the upper fork cover have to be installed at the same time as the fork, they can't be added after the fork is installed. This made pushing the fork throuth the bottom yoke and up into the top yoke almost impossible. I then came up with the idea of getting an extra long fork top bolt and using it to pull the fork up inside the yoke from the top.

Bolt and small waste section of mountain bike steerer tube as a shim.

I use the long bolt without the shim first and pull the fork up as far as I can. Then I remove the bolt and add the shim and repeat. Once that has moved the fork as far as it can, the stock fork top bolt is long enough to engage with the threads on the top of the fork and seat the fork fully. Simple!

Here it is with the stock bolt in place.

Both forks back in place. I've left the bottom yoke loose until I get the mud guard back on and the wheel in place so I don't clamp the forks before they are aligned.

[OliverMatthews]

It's really interesting thread. I like how you restore your motorcycle. And I even would like to make something like that. I found one Honda CB350 1972 at https://thecustommotorcycle.co.uk/ad_category/honda-cafe-racer-motorcycle-for-sale/ but... I have seen that you bought your Honda at Ebay. Is it better to buy at Ebay or doesn't matter really

[fastbob]

Loving this thread . This is so remenicent of my first ever bike , a CB175 . It had been restored to exactly the same standard as yours right down to the colour .