125 compression

[noobi]

i had an off on the weekend and cracked the ignition cover, so i took that off and discovered that i could turn the engine over very easily with my hand by turning the ignition
is this normal for a 125?
it feels like it has very little compression, is it supposed to be like that to mellow out the power?
or do i need new rings?

any ideas would be appreciated

its an 07 ec 125 btw

[2 strokes 4 life]

Originally Posted by noobi

i had an off on the weekend and cracked the ignition cover, so i took that off and discovered that i could turn the engine over very easily with my hand by turning the ignition
is this normal for a 125?
it feels like it has very little compression, is it supposed to be like that to mellow out the power?
or do i need new rings?

any ideas would be appreciated

its an 07 ec 125 btw

Hard to say, It takes some effort but I can turn my 250 by hand, so mabe turnning a 125 without much problem is reasonable.

Anyone can conferm this?

[GMP]

Turning a 2-stroke over slow by hand allows compression leakage through the rings, thats why you kick it fast for a check with a guage which is what you should do.

[iancp5]

Silly thought - as you whacked that side - the crank is turning as well as the flywheel? You haven't broken the key in the impact? As GMP says you can turn it slowly but you should feel considerable resistance until the air leaks past.

[widebear]

Originally Posted by noobi

i had an off on the weekend and cracked the ignition cover, so i took that off and discovered that i could turn the engine over very easily with my hand by turning the ignition
is this normal for a 125?
it feels like it has very little compression, is it supposed to be like that to mellow out the power?
or do i need new rings?

any ideas would be appreciated

its an 07 ec 125 btw

Would you go to your mates for a question regarding a possible serious medical condition?, hook it up to a comp gauge for the correct answer and quit acting like a ?

[noobi]

Originally Posted by iancp5

Silly thought - as you whacked that side - the crank is turning as well as the flywheel? You haven't broken the key in the impact? As GMP says you can turn it slowly but you should feel considerable resistance until the air leaks past.

dont think thats the case, cuz i rode it away form the accident, and it ran fine, although it was in first cuz the gear lever was bent 180 degreed into the peg
so yes the flywheel is still connected to the crank, unless it broke on the way home while sitting on the trailer

[noobi]

Originally Posted by widebear

Would you go to your mates for a question regarding a possible serious medical condition?, hook it up to a comp gauge for the correct answer and quit acting like a ?

ok did the comp. test, measured 130-135psi
is that ok?

[iancp5]

Originally Posted by noobi

ok did the comp. test, measured 130-135psi
is that ok?

I don't know for a 125, you'd expect more for a 250 /300 but it sounds enough to start it to me.

[widebear]

Originally Posted by noobi

ok did the comp. test, measured 130-135psi
is that ok?

That may be a little low for sea level or it may just be the gauge, they can and will vary quite a bit I cant tell you spec because I dont know exactly what a healthy tiddler should be at, somebody will chime in I'm sure, If it starts ok your prob fine. Keep in mind that a worn piston can still give you good comp numbers. I did a leak down test on my mc and it showed zero leakage but the piston to bore clearance way, way out of spec.

[noobi]

i have been reading around and it seems that your supposed to hold the throttle at WOT and kick the sh*t out of it to get a correct comp. reading, is this right?
i did nothing with the throttle, and i was only kicking it like i would to start it, not like trying to start a hot xr 600 or anything