Compression??????

[Chreaus]

I had a friend check the compression on the 2001 vino for me.
He said it was maybe at 50 lbs. I don't know much about this.
The scoot didn't want to turn over cause of a low battery also.
is this why the compresson is low?
Any one with some info on this?
I'm learning more ever day, You guys rock!!!!!
Thanks

Ohh The chrome rims sure look nice!!!!! :cool:

[scooterconvert]

I would do that test over again with a good battery. The cranking power will effect the compression reading.

[Lennox]

use the kickstarter, this should be a bit more accurate.

[Chreaus]

I have not put the kick start back together yet(took it off for the variator mod)
I hope to do that soon. I've been too busy planing a vacation.
The response is great guys.
THANKS!!!!!!! :)

[Christian]

Well 50psi compression doesn't sound to bad, but we don't have anything to base this on. a car with 180 psi compression is good, but for a little tiny scooter, i would guess 50 is ok even though your battery is weak, Why are you checking compression anyway? are you trying to get more horsepower or something?

[str8dum]

with 50 psi, the motor shouldnt even start. Either your meter is wrong or you are not checkin it correctly. It should be 110+ psi

[XPS1210]

110-130 psi...



50 psi??? seriously it started?

[xraydino]

Will throttle position, while cranking effect the compression reading?

[StepVino]

Pretty sure that the throttle needs to be wide open, or you won't
have much air to compress. That might be your low reading right
there. Maybe it's different with 2 strokes? Too tired to look at
the service manual.... ;;p

[OldGuy]

Once again I don't have any experience with 2 stroke motors but the following things will effect compression readings in 4 strokes:

Warm the engine to normal operating temperature.
Use wide open throttle during test.
Make sure the battery is fully charged and the starter cranks properly.

Hope this helps,
OldGuy

[powerzombie]

This old guy agrees with the "Old Guy". Warm engine, wide open throttle and three kicks or a couple seconds on the kick starter. Now, don't forget that it's not a good idea to remove the plug, or tighten it too much with a hot engine, especially an aluminum head. est to wait for it to cool down for a half hour or so.

[Zuma-Zuma]

50 psi? Full throttle, 5-8 revolutions. Should build quick. If its 50 again, you probably have a stuck ring. You also must turn it over "quickly".

[Christian]

Sorry about the missinformation, I was wrong 50 psi is verry low compression you should have over 100 psi and you should check it with a warm engine to allow the piston rings to expand properly. My question to you is does your compression gauge have the valve core in it? or has it been removed? I have had this happen to me before, so before you throw your compression gauge in the garbage check this first. If it's still low I would agree with everyone else and say that your gauge is faulty. Also If your Scooter really did have only 50 psi compression it would be completely gutless.