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  • Standard heads or special

    I have the 78 standard and while doing a head job. I noticed my valves size and intake port shape are different from other heads. I believe the other heads are from a 79-80 special. Did Yamaha change the head design at some point. The exterior of the heads all seem to be the same. Should I try to use the newer designed head on my 78 standard. I'm looking for max performance.

  • #2
    E's Forever

    Everybody knows that the '78s are the fastest!!
    John
    Now: '78 XS1100E 750 FD Mod (Big Dog)
    '81 CB900C ( 10 Speed)
    '78 CB750F ( The F)
    '76 CB400F ( The Elf)
    New '82 Honda MB5 Ring Ding
    Then: '76 CB550K
    '78 CB750F
    '84 VF1100S
    And still Looking!

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    • #3
      Re: Standard heads or special

      The intake valves are bigger on 80 and 81's. The pistons are domed differently. The cams are different as well. Use the search engine here to find all about it.

      Originally posted by Mikes78
      I have the 78 standard and while doing a head job. I noticed my valves size and intake port shape are different from other heads. I believe the other heads are from a 79-80 special. Did Yamaha change the head design at some point. The exterior of the heads all seem to be the same. Should I try to use the newer designed head on my 78 standard. I'm looking for max performance.
      Skids (Sid Hansen)

      Down to one 1978 E. Stock air box with K&N filter, 81H pipes and carbs, 8500 feet elevation.

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      • #4
        78's have 9.2 to 1 compression verses 9.0 on later models.
        Have not got around to cc'ing the head to see if it's just the pistons or head (or a little of both) that are different.

        Unless your doing something fancy to the later head I'd use the original.


        mro
        welcome to XSland...
        got any pics of your E?

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