Results 1 to 3 of 3
  1. #1
    Member
    Join Date
    Jan 2006
    Location
    phoenix
    Posts
    10

    1995 Johnson 225 venom compression help

    My engine has 254 total hours and had a new powerhead installed at 125 hrs. The engine has started running rough when first hitting the lake during acceleration, but starts to run on all cylinders after a couple of minutes of running. I checked the compression this weekend with the following results (when looking at the back of the engine).

    Right cylinders, bottom to top, 105, 108, 112.

    Left cylinders, bottom to top, 97, 102, 105.

    I was alarmed that the left bank of cyclinders were all lower than the right back, and the lower left cylinder was low. All above numbers were cold.

    I warmed up the engine and received the following numbers:
    Right cylinder, bottom to top, 100, 107, 105.

    Left cylinder, bottom to top, 90, 95, 100.

    What do you guys think? I do not want to put a new powerhead on this if I only will get 125 of use. Any thoughts??? The boat is a 95' Stratos 201 pro.

    Thank you for looking.

  2. Member
    Join Date
    Mar 2006
    Location
    Houston
    Posts
    1,422
    #2

    Re: 1995 Johnson 225 venom compression help (boa)

    It is common to have differences in compression from 1 side to the other. Have you decarbonized lately? It would be a good idea . Decarbonize then see what the compression is. I prefer to run compression on loopers when they are warm. Do you see any fuel leaks any where on the engine,?

  3. Member
    Join Date
    Jan 2006
    Location
    phoenix
    Posts
    10
    #3

    Re: 1995 Johnson 225 venom compression help (rudetech1)

    Thanks for the response.
    I performed a decarb on the engine two months ago. I also posted both cold and warm compression numbers. however, the warm numbers were taken after running the engine at idle for about five minutes in the back yard on the hose.

    I expected the warm numbers to be higher/closer than they are. I have not looked close enough for fuel leaks, but I would assume I could smell them if I had a probelm???

Similar Threads

  1. Johnson Venom 225 compression ?
    By rchunt in forum Evinrude/Johnson Motors
    Replies: 3
    Last Post: 10-04-2011, 05:56 PM
  2. Compression 225 Johnson Venom
    By Swammp Thang in forum Evinrude/Johnson Motors
    Replies: 6
    Last Post: 03-21-2011, 06:57 AM
  3. Replies: 7
    Last Post: 11-04-2010, 03:15 PM
  4. 1995 Johnson Venom 200
    By kray274 in forum Evinrude/Johnson Motors
    Replies: 1
    Last Post: 02-17-2009, 04:02 PM
  5. 1998 Johnson Venom 200 Compression
    By Apraser99 in forum Evinrude/Johnson Motors
    Replies: 9
    Last Post: 01-22-2006, 01:05 PM