Thanks Thanks:  0
Results 1 to 2 of 2

Thread: 35hp Evinrude High Compression Head question

  1. #1
    Team Member
    Join Date
    Jul 2018
    Post Thanks / Like

    Default 35hp Evinrude High Compression Head question

    I believe I found a high compression head from a 1982 35hp evinrude on Ebay and went ahead and bought it. Looks like it has the almost 360 degree squish band that its supposed to have. Can I bolt this on to my 1994 30 evinrude without making any additional modifications? Also, does anyone know where I can purchase larger main jets for my carburetor? Looking to make my cowling breathe better and don't want to risk running lean.
    Attached Images Attached Images  

  2. #2
    BoatRacingFacts VIP
    Join Date
    Jan 2018
    Post Thanks / Like


    I too bought one of these heads after reading on here about the extra compression. I did a compression test on my stock 1994 30hp and got 118psi in both cylinders. I put the 1982 head on and sadly only got 105psi. I milled it a bunch (maybe 0.060”) I can’t remember. I had to reshape it inside a little to fit the the pistons. In the end I was able to get 165psi on a 0.040” over block. I use 93 octane mixed at 40:1. Stock timing. 63 jet. Here is a video of planing a head.
    Likes hydrospeed77 liked this post

Thread Information

Users Browsing this Thread

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

Similar Threads

  1. 30hp Evinrude High compression head
    By smitherik33 in forum Motors and Powerheads
    Replies: 0
    Last Post: 2 Weeks Ago, 01:06 PM
  2. Yamaha 50hp billet high compression head
    By Tsr in forum Motors and Powerheads
    Replies: 1
    Last Post: 01-15-2018, 04:57 AM
  3. Any up-date on high compression pistons in 59 cu. In. Mercury?
    By Hounddog in forum Technical Discussion
    Replies: 17
    Last Post: 11-22-2017, 07:23 AM
  4. Replies: 2
    Last Post: 04-06-2015, 06:22 AM
  5. head compression vs fuel octane
    By tsrt in forum Technical Discussion
    Replies: 13
    Last Post: 08-17-2008, 10:55 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