piston kit urgent help

[foxman]

hi all,i got a new yx150 piston kit and the 2 top rings have D and the other has DY stamped on them,which one goes to the top?

 

[rhysieboyy]

the letter goes to the top of the piston and im pretty sure each ring is only suited to one groove in the piston.or it was atleast when i put some pistons together the other day.

 

[foxman]

ya but which 1? D to the top or the other one with DY

 

[sam93]

Last time I rebuild my YX150 the thicker ring was the top ring.

 

[rhysieboyy]

the rings should be taper and will only fit one groove in the piston.so without putting the ring on just put the outer ring into the grooves and you will find out which one goes were.

 

[foxman]

no they both fit the grooves,the only difference between them is that they are both black and one is slightly thinner with a silver edge

 

[rhysieboyy]

silver edge one to the top then.

 

[foxman]

why? is that silver egde for it to beed into the cylinder

 

[sean01]

if one ring is slightly thinner than so should one groove...

silver edge will be top ring/compression ring, the silver edge should also be the same side as the letter and im guessing thats letter D

second ring is just a cast ring, its an oil scraper ring.

i install rings with the gap 180 degrees apart from each other..

 

[rhysieboyy]

sean,putting the rings 180 in the beginning is right but they constantly spin when the engine is running dont they?so is there any real point in setting the rings 180 apart??

 

[sean01]

some say they do spin some say they dont... i guess if the hone cross hatch is pretty flat then it will turn them more..

but placement is mainly for initial startup.

and i place the rings 180 apart in line with the gudgeon pin

 

[rhysieboyy]

ahk,from what ive been told they do constantly spin or else there would be a wear line from the ring gaps.but 2 strokes run a locating pin so that the ring cannot spin and snag on the ports?

 

[foxman]

cheers all,the one with the silver edge is only silver round the edge,top and bottom is black and it says d7,but will put that on top,thanks for ya help guys

 

[The_GDFP]

http://www.wiseco.com/PDFs/Manuals/RingEndGap.pdf

 

[foxman]

what are the torque settings for the yx150? i just tighten to be just over snug,would that be ok

 

[The_GDFP]

STANDARD TORQUE VALUES - METRIC SYSTEM