Results 1 to 7 of 7
  1. #1

    48cc dome on 1300 head = ? compression

    I have the riva pro heads and was wondering what compression 48cc domes would bring. Anyone know? also does anyone know of any cons to running these heads? i don't have them on yet i was just curious as to what everyone else thinks. thanks!

  2. #2
    Moderator RX951's Avatar
    Join Date
    Apr 2005
    League City, Texas
    On a GP1300R, 48cc domes (including OEM gasket volume) should produce 145-150psi compression at sea level.

  3. #3


    thanks for the info!! is there any performance increase to say a 160 or 170 psi head?

  4. #4
    Happily Self-Employed WFO's Avatar
    Join Date
    Nov 2005
    Houston, Texas
    170 psi is pushing the pump gas envelope...not recommended IMO

  5. #5
    spud's Avatar
    Join Date
    Jul 2006
    Oceanside, California
    The new R&D heads I bought say 45cc and they are supposed to be 150???

  6. #6
    Mongoose's Avatar
    Join Date
    Aug 2005
    R&d and Riva's heads are both 45cc, but Riva calls them 48cc, because that is what they are with the head gasket volume added to the actual 45cc heads.
    R&D's are 48cc as well when you stick the head gasket on.

  7. #7


    is there any performance increase in going to a 160- or 170-psi or greater head? i realize fuel octane will need to be increased in proportion. i'm just wondering if there are any hp benefits going higher than 150-psi.

Thread Information

Users Browsing this Thread

There are currently 1 users browsing this thread. (0 members and 1 guests)

Similar Threads

  1. WTB: Rec compression 1300 head
    By Full Throttle in forum Yamaha Classifieds
    Replies: 4
    Last Post: 09-18-2008, 12:19 PM
  2. GPR 1300 head gasket
    By jpa1300 in forum Yamaha PWC Performance (2-stroke)
    Replies: 2
    Last Post: 09-03-2007, 12:09 PM
  3. If 1200 Cyl are machined to 1300 do i need a 1300 head ??
    By GPR1200_syd in forum Yamaha PWC Performance (2-stroke)
    Replies: 8
    Last Post: 11-23-2006, 05:37 PM
  4. 1300 no compression rear cylinder
    By OCFZR in forum Yamaha PWC Performance (2-stroke)
    Replies: 25
    Last Post: 08-31-2006, 08:05 AM
  5. head compression, keyway..?
    By titi0314 in forum Yamaha PWC Performance (2-stroke)
    Replies: 9
    Last Post: 04-06-2006, 10:12 AM

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts