1978 CB 750K motor options. Looking for a used motor.

blparker

blparker

New Member
I have recently acquired a 78 CB750k. It has absolutely everything but the motor. Has all electrical, carbs, exhaust etc. So, my question is what model years are my options and anything else I should know? That may be a loaded question so be kind lol. I plan on rebuilding if need be, just need a little advice/ guidance and where I can begin my search.
Thanks.
 
Not sure where you're located but here's one in the Philly area.
http://philadelphia.craigslist.org/mcy/3952181671.html
 
I sent him a message so we will see. I am located in central Indiana. Hopefully they are willing to arrange freight options! Keep the suggestions coming.
 
blparker said:
I sent him a message so we will see. I am located in central Indiana. Hopefully they are willing to arrange freight options! Keep the suggestions coming.
Click to expand...

crate it and ship greyhound
 
There is a pretty kick ass yard in Indianapolis, I think it's called Re-cycle? There was also one in Fort Wayne but I don't know if that one is still open?
 
Note that the output shaft on your 78K motor is offset 10mm to compensate for the larger 630 chain that Honda started using in 1977. Your rear sprocket is also offset that same 10mm, and you'll see that the upper mount for your left rear shock has a 10mm "shoulder" on it to compensate. As such, you must use a 77/78 motor on your 77/78 frame. Otherwise, your chain won't be straight. Good luck!
 
Or, could I run a different sprocket/chain set up? Also, there may be the option of a 76 hub to replace my 78 hub since I am doing all new spokes. If any machining is needed, I have easy access to all of that.
 
I could swear there was someone selling a '78 750K motor in the classifieds. The '78 K models always catch my eye since I have one.
 
just make up an offset c/s sprocket easy peasy being as how you have machine access
better yet machine the cushhub if needed whatever but loose the gigantic chain go 520
 
You might be able to run a older wheel in the back that has the shorter sprocket carrier, but you'd have to use a spacer to make up the difference between the hub and the swing arm. You might even be able to use just the sprocket carrier from an older 750.. make sure you get the stepped spacer that goes between it and the hub though!

Mine is the opposite that you have: 76F bike running a 77K motor. Used the 10mm offset rear sprocket from CycleX.
 
Without being close to the bike at the moment, I wonder if there is enough material there to machine 10mm off to set that sprocket closer to the center of the wheel. Assuming that's which direction it needs to go. Or would it be easier to buy that offset sprocket and rotate it so that offset is opposite of the original design.
 
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