compression test

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earthmover

in the tire smoke
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am I doing this right ..I open carb all the up take all plugs out and turn motr...also I do it hot.....
 
Opening the carb isn't nessesary. If all the plugs are out you'll have explosive fuel/air mixture blowing out of all the cylinders, NO SPARKS ! The engine would turn faster and the battery would last longer.
Hot engine isn't required either. I usually check one bank at a time.
 
If you test with the carb open, the ALWAYS test with it open. Same if you test closed. I always test 4 strokes (8 crank revolutions) noting how fast the compression comes up on the first stroke, and where it levels out on the 4th stroke. Strokes 2, 3 and 4 should be pretty similar, the first stroke is lower because you have to fill the extra volume of the compression gauge.

I typically remove all the plugs first. Generally because I am doing a compression test as part of a tune-up and will be installing new plugs. The battery and starter will be happier.

Biggest thing is to always do it the same so you can compare results over time.
 
I would text with the throttle open, make sure the battery is fully charged, engine warm, all plugs out, run about 4-5 strokes on the gauge & i always check the 1st. stroke reading to see how far it jumped.
 
you won't have explosions, just pin open the carb, pull all plugs, hook up yer gauge and DON'T turn it over by key, jump it at the starter switch with the key off.
 
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