compression

Reply

  #1  
Old 12-31-03, 05:53 PM
Member
Thread Starter
Join Date: Oct 2003
Posts: 23
Smile compression

Hello guys
My question is about compression.
What should be the compression reading
for a 4 cycle engine.Also for a 2 cycle engine.Finally got me a compression gauge to test with.Was needing to know a good compression to go by.I figure the cycles may be diffent. Thanks again for the help. mowerman
 
Sponsored Links
  #2  
Old 01-01-04, 09:34 AM
snoman's Avatar
Member
Join Date: Dec 2003
Location: mb, can
Posts: 326
mowerman
I'm interested in hearing what some of the replies to this will be cause with compression releases and stuff I don't know how to achieve this either.

snoman
 
  #3  
Old 01-01-04, 03:45 PM
jughead's Avatar
Member
Join Date: Oct 2003
Location: Davenport, Iowa
Posts: 597
I've put a compression tester on lots of engines (2 and 4 cycle) and usually find between 80 and 110 lbs on a good engine. Even the Tecumseh with a compression release registers about 100 when being cranked by the starter motor. You could get a lower reading if you have to check an engine with a pull rope starter but even there I've been able to get 100 lbs on my tester on a variety of B&S, Tecumseh, Kohler, and Homelite engines. You could expect an engine to be hard to start if your compression readings get much below 70 or 80 lbs. Keep in mind that its always a good idea to make sure that your choke is off and the throttle wide open while doing a compression test to get unrestricted air into the engine so you can get an accurate reading. Failure to do the above could cause an inaccurate low reading and make you believe that there is something wrong with the valves or rings when everything is really fine.
 
  #4  
Old 01-01-04, 10:10 PM
cheese's Avatar
Forum Topic Moderator
Join Date: Jul 2001
Location: USA
Posts: 16,818
I agree that 80 lbs should be enough to start most any gas small engine. Compression release can be a factor in the readings, how fast the engine spins can also affect it. I don't use a compression guage much anymore. I like to hear the engine turn, and feel it (if it's pull start). That has proven more useful to me than a compression tester.
 
Reply

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Thread Tools
Search this Thread
Display Modes