Topic: 77 cb750 camshaft (r2) same as 78cb750?

[shoemanII]

hi all,
camchain sprocket bolt backed out and busted the camchain, sprocket and cam - ouch!  found a cam on ebay from a 77 cb750k and is designated "r2".  will that work in my '78 750K?

also looking for one small head bolt (is one of four), the ones that hide under the rubber plugs.  someones' been in there before and nearly rounded it off.  got it out but don't dare to out it back in.  thanks much.
bobp       

[eurban]

The camshaft from the 77 should work just fine and is probably the same as your 78.   I don't recall whether or not the bolt for the cylinder head is a specialty type bolt or not.  Most likely you could replace  it with a quality grade 8 metric bolt of the same size and type. There are also a number of sites that offer online parts diagrams for our bikes so you could look up the part and order it.  Try www.crotchrocket.com for instance.  Good luck.

[bryanj]

R2 is nothing more than a casting number and means didly squat in relation to profile or tuning

[shoemanII]

thanks very much for your quick replies, am going to start sourcing pieces/parts and hopefully get 'er back on the road where she belongs.  the camchain sprocket bolt back out, and locked the cam up at idle.  took out the mounting flange on the cam, snapped the chain and busted the cam chain sprocket too.  no marks on the piston tops/valves tho, maybe i got "lucky".

to keep my sanity, am blasting the dirt/logging roads here in vt on a just-purchased husky te610e.   
bobp