CA77 flat tracker?!

[kungfutoast]

Hi all,
I did some searching and haven’t found what I’m looking to learn. Please link me if I missed something.

I came up in a small lot consisting of a cl77 motored, ca77 motor (gutted from the waste up), a BSA crankcase and the cherry on top a ca72 dropped in what I think is a Cl77 frame (no titles). The bikes missing the exhaust, it’s driveline sprockets, and kickstart return spring. It’s pretty rusted up in the frame, but saveable. I’ve looked into the head and things looked clean and well oiled. I haven’t done a compression test yet. I’m also missing all the electrical. I have the reg/reg, ignition switch, and points. About all I need for a dirt track bike, which is my plan for the bike.

Has anyone on here built up a track bike like this? The motor seams to be mounted fine lack the upper motor mount - missing. I notice the engine sits slightly to the right at the down tube. Frame appears to be straight. Can these motors be bumpstarted with out a battery? Similar to the CB200 with its pma and capacitor inline. And are there any fun performance mods like using cb750 pistons etc?

Again, thanks for the input and pointing me to posts I have missed. I’ll post pic soon.

[kungfutoast]

Follow up.

Had a chance today to tear into this bike. Looks like it is a CL77 frame with some modifications to the battery box, seat and fender. The motor is actually a CA77. If I did my homework correctly it should be a 1962 engine. Everything looks good. I put together my shopping list, oh man, cables are the most expensive thing I'll need!?

Does anyone have exhaust headers for this year bike they want to part with? I really want to hear this thing fired up and see it on the road! The pipes are pretty much the only thing I need to buy in order to see life. I have two donor motors to part out as well. Happy to barter.

Before you ask, I threw an xs650 front wheel on there.

[G-Man]

Nice looking project. Just keep looking on eBay for the pipes. Getting the right ones could be expensive but you could pick up some stock CB or CA pipes to get you going.

Clearance for the single carb and a small filter might be a little trick but not impossible to fix.

Have fun!

G

Follow up.

Had a chance today to tear into this bike. Looks like it is a CL77 frame with some modifications to the battery box, seat and fender. The motor is actually a CA77. If I did my homework correctly it should be a 1962 engine. Everything looks good. I put together my shopping list, oh man, cables are the most expensive thing I'll need!?

Does anyone have exhaust headers for this year bike they want to part with? I really want to hear this thing fired up and see it on the road! The pipes are pretty much the only thing I need to buy in order to see life. I have two donor motors to part out as well. Happy to barter.

Before you ask, I threw an xs650 front wheel on there.

[Geoff Hastings]

I'm in the process of rebuilding a CA77 engine I picked up on ebay. Internally the engine is fantastic, has hardly any wear but every nook and cranny is full of sand. I thought, surely it's not been used off road but seeing that picture of the bike with a knobbly tyre it probably has.

[kungfutoast]

Thanks for the comments!

A friend handed me a set of CB77 headers but they are one little mill over size? Like I think I measured 45mm. Is there a size difference for a '62? There are some cheap busted ones on ebay I may grab just to get going. All else fails I'll fabricate a new set.

I'll keep posting as things develop. Today I buffed the tank and will paint it and the frame tomorrow with primer. Again, this is going to be a track/trail bike so I'm not to worried about classic restoration. I'd need a title to warrant that. * shrug *

Cheers

[kungfutoast]

Can someone tell me the diameter of the headers for a 62 ca77? I can’t for the life of me find the answer. I have some cb77 pipes that measure 45.5mm. They are seriously just too big. Or should I just spend an afternoon sanding off .2mm’s?

Or if there are compatible headers from a more common motor? Thanks for the feedback.

[G-Man]

Hi

I just measured....

CB77 44.4 flange 38.2 pipe
CL77 44.4 flange 38.2 pipe
C72 44.4 flange 38.2 pipe

I think you have found maybe some aftermarket headers.

G

Can someone tell me the diameter of the headers for a 62 ca77? I can’t for the life of me find the answer. I have some cb77 pipes that measure 45.5mm. They are seriously just too big. Or should I just spend an afternoon sanding off .2mm’s?

Or if there are compatible headers from a more common motor? Thanks for the feedback.