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how to test compression on 2 cycle engines


NAVYDAD's Avatar
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TX

10-15-07, 12:11 PM   #1  
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):

 
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10-15-07, 02:56 PM   #2  
Remove the spark plug, screw in a compression guage and crank the engine, check reading on the guage. Have a good one. Geo

 
repair_guy's Avatar
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10-15-07, 05:52 PM   #3  
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.

 
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10-16-07, 12:25 AM   #4  
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?


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God bless!

 
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10-16-07, 02:16 AM   #5  
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.

 
NAVYDAD's Avatar
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10-16-07, 10:37 AM   #6  
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).

 
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10-16-07, 10:45 AM   #7  
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 .

 
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