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Discussion Starter #1 (Edited)
1969 CB350 Restoration

This is the first bike I'll be working on so I'm starting a thread to keep track of what I've done/what needs to be done and hopefully get some help/advice along the way. I have a pretty minimal set of tools that I use for regular car maintenance and will just be getting stuff as and when I need it. Pretty much a complete newbie when it comes to motorcycle work.

I dont have any grand plans for it yet except to give it a new lease of life for now while keeping everything as stock as possible and use it as a daily commuter (Its < 5 miles to work anyway..). So its not going to be like most of the awesome and inspirational builds around here. But i'll try and do my best :D

When I got the bike, it was in pretty decent nick. Major issues were:
1) Front brake frozen
2) Burn residue of some sort on the tank. Rather large dent on the right side
3) Original tires. Pretty dry and cracked, definitely not safe to ride
4) Seat foam in pretty poor shape. Cover is decent with one rip.
5) Electric starter not working
6) No main stand
7) One sidecover missing

The good:
1) Most of it is original since it was a one owner bike and not used much. (6764 miles)
2) Starts up with 2-3 kicks and sounds great. Engine compression is higher than spec. (185 psi) but almost exactly the same on both cylinders. Im told this is just carbon buildup and should straighten out soon.
3) No major rusting as far as I can tell. Mufflers are in decent shape too (more on that later). All the chrome is in very good nick too.

Here are some pictures of the condition I got the bike in. Looks like people here love pictures :)

























 

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Discussion Starter #2
One of the first issues was jacking the bike up to work on. After some messing around and help from folks over here, got the bike up on some wood blocks supported by a floor jack on one side and a jack stand on the other. Heres how it sits right now:


I took the pipers mufflers off before raising the bike. The seem to be in good shape and should look just fine after some cleaning and polishing..







I notice that the pipes were slightly different. One has a collar and the other does not. Im guessing atleast one was replaced. Anyone know which ones from what year?



Also, the mufflers dont have any markings on them. They look pretty original but im not sure because I have seen ones with markers on them. Can somebody tell if the earlier models had markings on them or not and if these are original?
 

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Other things I've done so far:
Forks are off. Will be changing the oil and resealing them.


Fork covers and tank already sent for repainting. The fork ears were bent and I straightened them out.
Pulling of the tank was really messy because of the tube connecting the two sides. Lesson learnt and now I am very well acquainted with the smell of gas. The original tank has burn residue all over the bottom and on one side. You can see that in the original pics. I'll probably take some pics after I get it back from the painter. I sent it along with a NOS tank I found on eBay for matching. Since the coils sit right under the tank, I am guessing there was an electrical fire at some point which burnt the tank. The PO had it lined with some white stuff on the inside as well. So I decided to pull the carbs off and check them. There was a inline filter on one carb only for some reason :roll: The fuel lines looked clean and so did the carb floats and bowl.
Is it worth rebuilding the carbs at this point or should I just leave them alone since the bike seemed to be running fine?
Also, any other things I should check that might have been damaged by the burn?
 

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Front wheel..


The brake mechanism seems to be working smoothly. Need to replace the cable since its jammed and all attempts to restore it have failed so far.
I have ordered new brake shoes and will be replacing them anyway, since I believe this still has the original 40+ year old brakes.

Out of the other cables, the speedo/tach cables look good. The clutch and throttle cables have cracked sheathings so I will be replacing those.

Both the front and rear tires are the original bridgestones. Ordered new CST tires with matching tread patterns.

Ohh and please let me know if I miss out on anything as Im going through this..
 

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Glad you have 185 psi but the head is going to have to come off. You have to replace the camchain tensioner.

Trick to old frozen cables is to slowly bend but don't kink the cable. Back and forth all the way down. Then get some lube down once it is free.

Buy a new cable - just saying this works.

Looks like a real nice CB, I hope you ride the snot out of it.
 

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I noticed that the petcock was on in the pics. Just in case you were not aware. These bikes can leak fuel via the carbs into the oil not a good thing to happen. Well worth getting into the habit of every time you stop its fuel off before key out :D :idea:
 

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Discussion Starter #9
LashLarue said:
Glad you have 185 psi but the head is going to have to come off. You have to replace the camchain tensioner.

Trick to old frozen cables is to slowly bend but don't kink the cable. Back and forth all the way down. Then get some lube down once it is free.

Buy a new cable - just saying this works.

Looks like a real nice CB, I hope you ride the snot out of it.
Do I absolutely have to replace the camchain tensioner? I was going to adjust it with instructions from the manual. Is there a way to tell if it needs replacing?

Thanks for the tip on the cable. I'll try that out.

And yes I do intend to ride it a lot :D
 

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Discussion Starter #10
nigelrharris03 said:
I noticed that the petcock was on in the pics. Just in case you were not aware. These bikes can leak fuel via the carbs into the oil not a good thing to happen. Well worth getting into the habit of every time you stop its fuel off before key out :D :idea:
I'll definitely keep that in mind. Thanks!
The pics in the first post are from the PO when he ran the bike. Petcock was off when I got the bike.
 

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Looks like a good bike you found and it looks like you are off to a flying start. While you have the carbs off I will take them apart and make sure everything is clean.

I am currently looking for a 350, but not that easy to find here and definitely not in the same condition as yours :mrgreen:

Enjoy the build and then the riding.
 

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Thanks guys!
I plan to do a full carb rebuild. Have the gasket kits from Honda in hand now.

Meanwhile..I opened up the clutch cover and look what I found...
[attachment=0:3vh9r8xn]IMG_20130727_170653_912.jpg[/attachment:3vh9r8xn]

I have never seen so much concentrated gunk on a vehicle before! What is the greenish stuff in there? Is this normal?
 

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Discussion Starter #14
Time to wake this thread up from the dead..
I have decided to do a full restoration. The main reason was that I found that the bike had sat with a leaking battery for some time. This has eaten through the paint and the frame has started to rust just under the battery tray.
[attachment=4:4mvpyprp]IMG_20131013_225643_150.jpg[/attachment:4mvpyprp]

I thought if I have come this far might as well go all the way. So the frame is completely stripped down. I am going to send it for powder coating.
Meanwhile, I will rebuild the engine and install a bullet proof cam chain tensioner at the very least. This will be the first time I am ever looking at the inside of an engine :)
The cylinder head is already out. The bores look in good shape to my untrained eye. There is a lot of carbon buildup on the pistons, which explains the high compression.
[attachment=3:4mvpyprp]IMG_20131013_231418_826.jpg[/attachment:4mvpyprp]
[attachment=2:4mvpyprp]IMG_20131013_231430_938.jpg[/attachment:4mvpyprp]
[attachment=1:4mvpyprp]IMG_20131013_231446_419.jpg[/attachment:4mvpyprp]
[attachment=0:4mvpyprp]IMG_20131013_231509_716.jpg[/attachment:4mvpyprp]

So, my first question is, what do you guys think is the minimum I need to do with the cylinders/pistons? I am already way over budget on this bike and would like to keep it reasonable without cheaping out on stuff.

And the second question, how do I get the cylinders off the crankcase? They are stuck on there good. The pistons are moving freely inside, so pretty sure thats not the sticky part. There seems to be no good leverage point to try and pry them off. I dont want to use a screwdriver or anything sharp to pry it because that might damage the mating surface with the crankcase. I tried giving it a few taps around the fins at the corners with a deadblow hammer. Admittedly the taps have been reasonably gentle since I'm afraid of damaging the brittle fins. So is there a trick I'm missing here?
 

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I've found that the super toxic spay carb cleaner is great for dissolving shellac/ gasket bond so spaying it around the mating surfaces helps loosen well stuck surfaces

I have 0 experience with 350's but in general your going to need to clean the carbon off the piston tops, check the bore,piston wear and ring gap, and if all is in spec rebuild with a light hone
 

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I used a 3" wide putty knife perpendicular to the seam. I put the blade dead in the center of the gasket material and gave a gentle "tap". Cylindrrs separated instantly, first tap. This was after they wouldn't budge with the dead blow hammer trestment. Make sure if there is a cylindrr retainer bolt it comes out first.

Sent from my LG-LS840 using Tapatalk 2
 

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Simo said:
I have 0 experience with 350's but in general your going to need to clean the carbon off the piston tops, check the bore,piston wear and ring gap, and if all is in spec rebuild with a light hone
+1
 

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Discussion Starter #18
Thanks guys! I'll ask around for recommendations on a good machine shop nearby and take the cylinders and pistons over to them for measuring and honing if needed.

CB200T75 said:
I used a 3" wide putty knife perpendicular to the seam. I put the blade dead in the center of the gasket material and gave a gentle "tap". Cylindrrs separated instantly, first tap. This was after they wouldn't budge with the dead blow hammer trestment. Make sure if there is a cylindrr retainer bolt it comes out first.

Sent from my LG-LS840 using Tapatalk 2
Thanks for the tip! I am not sure about the cylinder retainer bolt you mention. As far as I can tell looking at the parts fiche and manual, there isnt one the the 350 engines. Can someone confirm this?
 

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Discussion Starter #20
Spent the last hour alternating between trying to insert a putty knife into the gasket material and a few gentle blows with the dead blow hammer. The gasket material has really hardened and the putty knife is not making much of an impression on it. Im afraid if I try and jam the knife in it will end up scraping the surface.
Any other ideas? Should I just keep going at it with the hammer?
 
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