New top end rebuild question? SOAP & Water

[Speeddrive1]

Are you sure the piston is in the right way ( there should be an arrow on the top of the piston)?

Does this motor use reed valves and if so are they bad?

[Doctorturbo]

I was wondering if anyone has experienced or has heard of anyone having problems getting compression after having their top end bored and honed because they did not wash the jug/cylinder good with soap and water before reasembly. Thus being to slipperry for the rings to grab, resulting in air passing the rings causing the atv not to fire.

Throwing the BS flag on this one. It's at full mast. No way no how.

Did you ever do the leak down to find out what the numbers I wanted are?

[kellyisu]

I have to say my bad about saying that the tech told me I didn't deglaze. He told me to wash the cylinder out good with soap and water first then clean it out- I thought that was deglazing after doing some reading, my bad. So, the tech told me to wash the cylinder good with soap and water then clean it and to give that a try. Doctorturbo- I may have not explained things right the first time- sorry-

Piston is installed with arrow pointing to the right towards the stator/exhaust side.

No reed valves.

I used NE gasket sets- has anyone used them? I just looked to see which way it looked they fit properly and slapped them on. The bottom top end gasket( blue 4 bolt pattern) fit on nice and easy and the upper topend gasket(darker thicker 6 bolt pattern w/ center ring) fit on real tight to where u had to pretty much do a cross pattern to slide it down each bolt individually carefully so you did not badly damage the gasket on the threads- IS THAT HOW THEY NORMALLY FIT?

I never did the leak down, because the presure it was loosing was drastic, probably only reading like 30-40 psi. So, I figured it had to be either improper boreing and honing/ specs/ rings/ piston.

SERIOUSY- Thank You for all your help guys- I kinda feel like I am running you all in a circle, but I am getting there.

[MrMarty51]

Ring end gap is very critical.
Remove the rings from the piston and slide them 1/2 way down the cylinder making sure the ring being checked is paralell with the head surface of the cylinder,use a feeler guage to check how much end gap there is between the ends of the rings.
If the ring ends are touching it could cause the rings to "warp" in the cylinders and leak compression.
If the book calls for 10 thousandths end gap give em 12.a bit too much is better than a bit to little.

[Doctorturbo]

Doctorturbo- I may have not explained things right the first time- sorry-

No problem. I, just like you want to get your ride on the trail again.

Some posts real interest me. This is one of them. If it's leaking as much as you say it is you should see something. I've built a lot of engines and have seen a lot of worn out engines and even ones with rings that come out in pieces don't have too bad of a compression readings.

Here is a few things to do:

Take the piston off of the rod and stick it in the bore. Shine a light on the bottom side of the bore. See any light?

Take the rings off of the piston. Stick them in the bore and see what the gap is. It should not be much more than the pin width on the piston.

Just some things to check. Good luck and let us know.