Piston Ring Installation (Top & 2nd)

[lmarkie74]

I have purchased a piston ring kit for my JN6 301cc Motor. In the kit, one ring is completely coated. The other ring is coated black with a silver coating on the diameter and about .25mm on the top and bottom sides.

Which one is the Top ring and which one is the 2nd ring? Or does it matter?

Thank you,

[CP241]

The ring with the chrome outside will be the top ring.

They are also marked top and bottom. Make sure they point the correct direction

[Ktrilla]

I may need to replace my rings. Is there a good thread that discusses how to do this on a Yamaha G9? And, is this project something that is pretty simple to do?

[CP241]

Originally Posted by Ktrilla

I may need to replace my rings. Is there a good thread that discusses how to do this on a Yamaha G9? And, is this project something that is pretty simple to do?

Best bet is to download the repair manual. I found it on Google when I did mine.

[Ktrilla]

Thanks!

[lmarkie74]

Originally Posted by CP241

The ring with the chrome outside will be the top ring.

They are also marked top and bottom. Make sure they point the correct direction

I did some research on the internet on piston ring manufacturers. You are right. Chrome goes on top for the reason that it resists heat and abrasion more than the cast ring. The cast ring is manily for oil scrapping. I looked on both of rings, there are no markings. Profile is rectangular with no bevels or chamfers what so ever. Motor is running now since I put it back together. Problem I am having is that it bogs down and is not responsive. I'm betting carburator problems. Runs good with the choke pulled out so that is an indication that the fuel mixture is lean. Jets?

[Dave in VA]

Is the stock air filter in place?

[CP241]

Originally Posted by lmarkie74

I did some research on the internet on piston ring manufacturers. You are right. Chrome goes on top for the reason that it resists heat and abrasion more than the cast ring. The cast ring is manily for oil scrapping. I looked on both of rings, there are no markings. Profile is rectangular with no bevels or chamfers what so ever. Motor is running now since I put it back together. Problem I am having is that it bogs down and is not responsive. I'm betting carburator problems. Runs good with the choke pulled out so that is an indication that the fuel mixture is lean. Jets?

Make sure the air box is complete as in not missing any of the parts. And make sure the lid is 100% completely sealed or it will run great on choke, but run like dookie with no choke