95 CR125 Compression Test

[jammin-johnny]

My friend has a 95 cr125 and I took a compression test on it and got a reading of 165 psi. To get that reading I had to kick the bike for roughly a minute straight or more. Should the reading take only a few kicks or does it not really matter? I just don't know if you kick till the gauge stops moving or if you kick it 5 or 10 times.

 

[marcusgunby]

Normally you get about max pressure with less than 10 kicks

 

[reelrazor]

Four kicks is what I give them. How the gauge rises tells me as much as how far it rises. When the engine is in good shape usually three kicks does the vast majority of the rise, four is just for good measure.

Gauges and techniques vary so compression numbers are pretty subjective. raw compression numbers alone don't mean all that much to me. At my shop, anything that has the plug(s) out of it gets checked and noted on the work order. That way when it is back in my shop I have a baseline to go against( I deal with a lot of triples-sleds).

My own stuff gets checked a) right after buying new-or rebuilt. b) at regular intervals afterwards.

When I see the numbers falling off it is time to order in refreshing parts. If the run condition goes to hell, again I have a baseline to help my evaluation.

 

[darringer]

I usually kick it until it stops rising. That takes between 7-10 good forceful kicks.