how to test compression on 2 cycle engines

Reply

  #1  
Old 10-15-07, 12:11 PM
NAVYDAD's Avatar
Member
Thread Starter
Join Date: Jul 2006
Location: usa
Posts: 81
Unhappy how to test compression on 2 cycle engines

I recently acquired a McCulloch chainsaw(neighbor) and it's fairly new. I would pull the starter rope and there seems to be no resistance.could it be the compression is bad & how do I test this.I tried to take off the clutch but I can't seem to take it off .(any suggestions):
 
Sponsored Links
  #2  
Old 10-15-07, 02:56 PM
Member
Join Date: Jun 2006
Location: St. Louis
Posts: 2,365
Remove the spark plug, screw in a compression guage and crank the engine, check reading on the guage. Have a good one. Geo
 
  #3  
Old 10-15-07, 05:52 PM
repair_guy's Avatar
New Member
Join Date: Apr 2004
Location: Marion,Al.
Posts: 539
Or if a gauge isn't available you could just press your thumb aginst the spark plug hole,crank the engine over and if it forces your thumb away with a noticable pop then there is compresion.

NOTE: This test doesn't tell you weather you have enough if your not experanced.Just weather it's their.geogrubb's gauge is the best to use for that.
 
  #4  
Old 10-16-07, 12:25 AM
cheese's Avatar
Forum Topic Moderator
Join Date: Jul 2001
Location: USA
Posts: 16,813
If you feel no resistance, then it hasn't enough compression. No guage needed if it's that bad off. Are you certain the spark plug is in it?
 
  #5  
Old 10-16-07, 02:16 AM
puey61's Avatar
Member
Join Date: Apr 2004
Location: Upstate New York
Posts: 3,224
Why do you want to remove the clutch? There should be no need to, however, you should consider removing the muffler to have a look at the condition of the piston and cylinder though if you suspect low compression.
 
  #6  
Old 10-16-07, 10:37 AM
NAVYDAD's Avatar
Member
Thread Starter
Join Date: Jul 2006
Location: usa
Posts: 81
McCULLOCH chainsaw

Thanks for the info,Iwas trying to get the clutch off to get a better look at the cylinder, I took off the spark plug and notice that the piston had some carbon build up and the walls seem to be scuffed (black). It looks to Me that this saw got hot & not enough oil mixture?Do You think this saw could be savaged ,And if so what can I do( please advised).
 
  #7  
Old 10-16-07, 10:45 AM
NAVYDAD's Avatar
Member
Thread Starter
Join Date: Jul 2006
Location: usa
Posts: 81
McCulloch chainsaw

I didn't remove the muffler but I'll try that out today and see if the inside is bad ,it seems to Me that pulling on the cord is too easy and not hard .
 
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