The Jack's Small Engines Forum - Join Our Online Community
Jacks Small Engines Lawn Mower & Power Equipment Forums
Reply to post

Hot!No compression

Author
Post
Essentials Only Full Version
JGITTOES
New Member
  • Total Posts : 2
  • Scores: 0
  • Reward points: 0
  • Joined: 2024/06/03 07:20:06
  • Status: offline
2024/06/03 07:36:17 (permalink)
0

No compression

Hi,
 
I have a 3hp B&S engine on a water pump that has 0 compression.  A bit of a long story.  The engine last ran in 1989 and has sat since.  The engine maybe has 200 hours on it as it was also purchased in 1989.  As a project I want to see if I can get it going.
 
I took off the head and verified the valves are not sticking.  I changed the head gasket but that made no difference.  I cleaned up the valve seats and they look good too.
 
I did notice that when the intake valve is fulled seated I can turn the top of the valve with just my finger.  This is not the case with the exhaust valve.
 
Before I pull things apart to get to the springs anyone has any other suggestions at thing to look at?
 
Since it sat for 30 years will that mess up the springs?
 
Thanks,
Jon
Quote  #1

4 Replies Related Threads
    SRTsFZ6
    Super Member
    • Total Posts : 2081
    • Scores: 74
    • Reward points: 0
    • Joined: 2018/11/18 07:20:58
    • Status: offline
    Re: No compression 2024/06/03 07:45:01 (permalink)
    0
    JGITTOES
    I did notice that when the intake valve is fulled seated I can turn the top of the valve with just my finger.  This is not the case with the exhaust valve.
     
    Before I pull things apart to get to the springs anyone has any other suggestions at thing to look at?
     
    Since it sat for 30 years will that mess up the springs?
     

     
    What does the exhaust valve do?   Seats fully/can't move with finger, or not closing fully?
     
    If you cleaned up the valve seats, what are the valve clearances?
     
    .

    Scott
    Quote  #2
    Mikel1
    Moderator
    • Total Posts : 1174
    • Scores: 41
    • Reward points: 1
    • Joined: 2016/04/14 18:48:53
    • Location: Georgia
    • Status: offline
    Re: No compression 2024/06/03 11:47:46 (permalink)
    0
    Zero compression, is the piston going up and down? Bad compression tester perhaps
    Quote  #3
    JGITTOES
    New Member
    • Total Posts : 2
    • Scores: 0
    • Reward points: 0
    • Joined: 2024/06/03 07:20:06
    • Status: offline
    Re: No compression 2024/06/03 12:26:01 (permalink)
    0
    Thanks for the replies.  The piston goes up and down no problem.  I checked the compression tester on another engine and it have a reading of 80psi so I think that is ok.
     
    Upon looking closer the exhaust looks to have a little clearance and not fully closing.  I certainly can't move it with my finders.  Once I find my feeler gauges I will check that that out.
     
    Thanks again
    Quote  #4
    Mikel1
    Moderator
    • Total Posts : 1174
    • Scores: 41
    • Reward points: 1
    • Joined: 2016/04/14 18:48:53
    • Location: Georgia
    • Status: offline
    Re: No compression 2024/06/03 13:25:33 (permalink)
    0
    Okay, if you add about a teaspoon of oil into cylinder do you get a reading on your tester?
    Quote  #5
    Jump to:
    Copyright © 1994 - 2016 Jacks Small Engine & Generator Service, LLC
    © 2025 APG vNext Trial Version 5.5