I just measured, engine cod, throttle wide open...a weak 90psi came out, same on both sides. It could hold that figure without a trouble, but wouldn't get higher.
Do I have to hurry to get a new top end, or can I wait until next winter (So I get a powervalved top end!!!)?
Thaks for any input about this compression stuff.

 

Thats pretty low man.. I'd at the very least throw new rings in it.. my blown up banshee with one piston had more than that!lol!

 

Keep it low Zorro...keep it low!
(at least for one drag race)

 

probly not going to blow yet but ideal psi is 110- 120.. 2 strokes do not run well under 100.. atleast on sleds they are like that..

 

I have got to agree with Xplor. I think that sounds good to me

NOT


KD

 

Do you know that the guage you used gives good readings? It may just be reading low. Check someone elses using the same guage. Anyway, if the reading really is 90psi I wouldn't worry too much. Since both cylinders read the same, nothing is 'broken'. Just normal wear. At some point the bike will become hard to start due to low compression. At that point you have no choice.

 

My dad run his banshee with 90psi all summer last year when we put new pistons in two years ago one side had 60psi and the other was 90psi that was with the stock pistons one side only had one ring left but the piston was shot it didnt even scrach the jug at all he didnt even have to bore it.

 

How strong does it feel? Runs good still I take it?
For security...I would pull the pipes and at least take a look into the ports....you should be able to tell if things are getting funny inside there.
As mentioned above...it's just a matter of time before it starts to get hard to start. I might be sceptical of the gauge too...since it seems to be reading the same (or close) value for both cylinders. Is the gauge a screw in type? or just push to fit(rubber nipple)

 

I lent Zorro the guage. It is new. It is the screw on type with a rubber gasket. My Scrambler showed 138 psi, which was just about right for the type of mods I am running. Maybe it wasn't screwed in right...his shee felt mighty strong to me today!

But then again...he was running Polaris oil!

 

I too have doubts about my way of putting the gauge. Thegauge itself must work perfect since it's brand new (actually, it's Xplor's ), and he got a 138psi reading on his scram. So the gauge is correct. It's a screw type, but I might not be tightening enough...I got 90 psi on both sides, the same reading on my sled (whose cylinders should be redone)...gonna try on my dad's sled (which seems to need a rebuild too...if you go tto the conclusion...do ALL your machines need a rebuild? the answer is yes ), see if I get something else than 90...
Other than that, it starts perfect...I was just curious to see when I could get a new topend (obviously upgrading to powervalves)...hehe.
Oh well, doesn't seem to be anything to be worried about