Topic: CB750 CAMS

[youn6372]

Does anyone have any information concerning the lift and duration of the all CB750K cams.  Im trying to figure out what the difference is between say an R1 and an R9 or R8.....

Thanks for the help.

[ekpent]

In past discussions here I think it has been determined that those casting numbers do not correlate to any specific type of cam as far as lift etc but may mean which specific mold they were made from.Different number cams have been seen in same year bikes. The best bet is to have an original cam from a know engine from a know year to assess that info.

[youn6372]

Ok so if thats the case and info on the lift for specific years?  I've heard that as the bikes aged from 69 to late 70s they became "greener" and the performance decreased.  I'm asking because I just pulled a cam stamped R9 out of a 73 and I've never seen it before.  The cam itself was toast so I put in one from a 77...

[ekpent]

I think that the cam from the 77 may be slightly 'hotter'.Early cams from the 69-71,maybe 72 had a little different or hotter profile also.Not an expert on these but the 77 may be the same profile as the 75-76 F models also.
   What happened to the old cam,was there a blockage in the head that spun out a bearing area?

[Jerry Rxman Griffin aka MuthaF'er]

You should notice a definite difference! The 73 - 76 K was probably the mildest. I think it was more for longevity than the green thing. Were we being green in 73? The cams began improving again with the 75 & 76F whivh carried over in the 77K