T-BAG’s CB450s…

[T-BAG]

What up guys? Been lurking for a while thought I’d make a thread. About a year ago I bought a couple frames and parts to hopefully build a café of some sort. They are a 71 CB450 and a 72 CB450. Last week I acquired a 69 CL450 and I’ve noticed some differences that I wasn’t expecting like fork and headlight sizes, don’t know if this is because it’s a CL or just because it’s older? I have 2 motors, the first one came with the CBs, I pretty sure the bottom end and cylinders are in good shape, PO said it had good compression and I believe he knew what he was talking about but the top end is slightly taken apart, he told me it needs stem seals and such.

The CL I got last week had been sitting under a 4x8 sheet of plywood for 20 years along with a few other bikes, I picked it up for $200 with a seized motor. Pulled the plugs and put some penetrating oil in the cylinders and it broke free fairly easily. I am getting compression out of the right cylinder but not even a pound out of the left. This is only using the kick to try and get a reading, I haven’t been able to get the electrical system to do anything yet. I am assuming a valve problem since there is zero compression and since I’ll have the head off I might as well take care of the cylinders while I’m there.

I think I will try and fix the motor I got with the CBs first since it is already taken apart and I believe it has less problems, I have no experience with these motors so I’m trying to keep it simple. I have done a couple top ends and a complete re-build on cars before though so I’m not completely useless. Any tips on where to start?

Here are some pics of what I have to work with, I am thinking about doing a rat bobber with the second motor if I ever get this one done…

 

[Hoosier Daddy]

Get a manual, they are available in pdf you can download for free if you search.
Take lots of digital pics along the way, you can refer to them later on re-assembly.
Safe bet the one with no compression has a stuck valve or a broken ring from being siezed, she'll need to be taken down for sure.
Good luck to you, seems you ought to be able to make at least one awesome bike out of all that!

 

[T-BAG]

I did get the manual in PDF, looks like it will be a big help. Thanks

Well I went out to take a look at my first motor to see what's what. Previous owner had written down what he was going to buy to put this back together... "valve guides, valve guide seals, and a cam chain link" and he gave me a gasket kit for it. I took pics of all the parts I have so I could put them up and have you guys look at everything, tell me what you think. What needs to be done? Anything look out of the ordinary? Any missing parts that I need to look for? I'd like to just clean everything and somehow do whatever needs to be done to get the head back on correctly.

Just look a little dirty...

I think someone tried to port it a little?

Intake...

Exhaust...

Right Intake...

Left Intake...

Right Exhaust...

Left Exhaust...

 

[OneArmWillie]

A lot better condition than when I got mine.

 

[T-BAG]

I'm taking it to the machine shop tomorrow to find out about valve guides, it does need them badly. Maybe a hone also if they say it needs it, the cylinders look pretty good to me but we'll see what they say. May have to find a set of valves too.