Installing piston rings

[tricci]

I read in Eric's book that the piston rings should be installed with the letter markings facing upwards. My YZ 250 rings don't look any different from one side to the other. My Yamaha shop manual doesn't say anything about the proper placement of the rings.

I was just wondering why you should put the piston rings in with the letter markings facing upwards.

Thanks

 

[viking20]

IF the rings needs to be fitted in a certain way,there will be marks,and they should always face up.A piston will always be fitted with the mark on the crown facing the exhaust,unless its marked "in" off course!In a 4-stroke,the rings will usually fit one way only,if installed wrong-lots of blow-by and oil will enter the combustion chamber.These "rules"are a kind of standard,bikes,cars,boats,diesels,whatever.....

 

[Ol'89r]

Originally posted by tricci

I was just wondering why you should put the piston rings in with the letter markings facing upwards.

tricci.

Depending upon what model bike you have, some rings have a taper or step to them where they contact the cylinder. This helps seal compression and control the amount of oil on the cylinder wall. Some rings also have a step or taper on the inside where they fit into the piston ring groove for the same reasons.

If you were to put the ring in upside down, you would defeat the purpose of the ring.

Just my $ .02

 

[tricci]

I kinda thought the same thing about the taper on the rings but as I examine these rings they look exactly the same from both sides. Maybe it's close to microscopic and you can't see it with normal observation. The strange thing is the manual says nothing about it.

BTW I have a 2000 YZ 250. If that helps.

 

[marcusgunby]

I have never done a YZ but all other brands have a small stamped letter on the top of the ring.

 

[bclapham]

whhooops! i never saw any letters stamped on my YZ rings either, but i dont remeber looking that hard! Good job ive talked myself into doing a topend soon! another lesson learned, and an extra bit of wisdom!