'72 CB350 Cafe

Hey all, I wanted to introduce myself and my new project bike! I've been seeing all sorts of sweet cafe racer projects all over the internets and thought it was high time I try to build one of my own. And as a lifelong fanatic of cars of bikes who's never torn down an engine, i thought I owed it to myself to finally just DO IT.

After scouring craigslist for a few weeks, I came across this CB350 that I would make mine. (Yes that is the living room of my apartment that I've turned into a makeshift workshop)



Another shot of the living room workshop. I have the most understanding wife in the world.


One down, one to go:


As some of you have probably found, the phillips head screws are all disasters and half of them get stripped when you try to take them out. Screw extractors work 99% of the time, but for that 1%, time to break out the welder.


Tore down the engine, looks like I'll need new pistons!


Anyway, I plan to contribute some good progress reports to this thread, but more often than not, I will probably be asking for help! (My next post will be a case in point.)

As promised, here come the questions!

Here are images of the wear on the cylinder side covers where the camshaft rests. Is this a problem?




Camshaft lobe measured at ~39mm (the rest were close). How come the shop manual says it should be 36.858-36.898mm?


Camshaft mounting end measured at 21.91mm at one end and 21.92mm at the other. Manual says to replace if under 21.92, should I be looking for a new camshaft?



Measured the rocker arm pins but didnt take pictures. They were all towards the low end of the range, with one being 12.8mm vs. 12.9mm in the manual. Should I be looking for those too?

Alright, been making some progress, slowly but steadily.

Dismantled the engine, cleaned it, and powdercoated the engine covers:







Now just finishing up on the crank cases.

Also, when i took apart the engine, i found that the timing chain guide broke off and got ground down by the chain:



I found pieces and shavings of it inside the lower crankcase and dug out a bunch of it from the oil filter. It's really tough to get inside the nooks and crannies of the lower crank case so I'm wondering, between the centrifugal oil filter and the mesh screen on the intake of the oil pump, am I okay leaving it like this?

I am putting the engine back together and am about to bolt the camshaft to the cam sprocket. However, i am having trouble lining the LT mark up to the index on the stator. When I let go of the crank, it wants to rotate just past the LT mark. Also, when i peek through the spark plug hole and rotate the few degrees between the LT mark and its natural resting position, the piston does not move. Is there supposed to be some rotational play in the crankshaft?

Clamp a wrench to hold it at TDC

SONIC. said:

Clamp a wrench to hold it at TDC

Click to expand...

That's what i was planning on doing, but just wanted to make sure that there wasn't a problem with the crankshaft. Thanks!

Been awhile, but i've got some progress to post!

New pistons in!


Engine almost all the way there.


Powdercoated the passenger peg mounts to be repurposed for rearset mounts.


New bronze swingarm bushings and powdercoated swingarm.


Rims waiting for powder.


Powdered rims with new tires and mounted on swingarm. Might just stop the build here and use it as a unicycle.


Powdered front springs


Mock up of the front forks - gonna ditch the ugly shrouds and show off the springs


Fabricated spacer rings to keep the springs centered on the forks and a surface for them to sit on since I'm ditching the shrouds


Question is, i've mocked up the whole front end (forks, springs, spacer rings, and upper and lower trees), and there's a big gap (about 2-3 inches) between the top tree and the forks. I could make some of that up by reducing the thickness of the spacer rings, but that won't take me all the way there. Is there some amount of preload to the suspension?

Grate looking build and you are maken some grate progress! But I cant lie the pic of the bike stock with the mud guard looks sweet and I would keep that endro look with maybe a flat brat style seat! But that's just me, grate things about motorcycles you can build them to be what ever you want!

She's lookin' purdy