On the O.S. Max four-stroke engines, there is no 'top' or 'bottom' to a brand-new piston ring. If you're installing a used one, then it does make a difference because of the wear it would have received during use. Used parts must always be installed the same way they came out.
As far as the ring gap is concerned, it makes no difference in the four-stroke engines where you put it. As the engine runs, the ring will tend to rotate around the piston. Because there are no ports in a four-stroke engine's sleeve, there's nothing for the ring's ends to get caught on.
We hope you find this information helpful. Should you have any further questions or concerns, please do not hesitate to contact us at this email address. (Please be sure to copy all previous emails into any future questions.)
DID YOU KNOW that our web pages now all contain FAQs? (Frequently asked questions) Please drop by and take a look! We hope you'll find the information helpful and valuable to you.
Bill Baxter, Manager
1610 Interstate Dr.
Champaign, IL 61822
Phone: 217 398-0007
Fax: 217 398-7721