OEM Piston rings??

[Jeff B]

Is it normal for the upper and lower cylinders to have different rings? It appears I ordered the wrong ones. I found three of the boxes from when I built it. Two labeled 47x-11610-20 and one 3xc-11610-20. The pin that prevents them from turning is located differently. Apparently I needed the 3xc for the lower cylinders.

[Jeff B]

CMS has them in stock listed for a TZR125 not RD500. I don’t recall ordering TZR125 pistons.

[steveho]

If TDR250 or TZR pistons are used (and that is common for the lower cylinders), then yes, you need the different ring type that suits the alternative location pin. I think Yamaha supply these pistons in lieu of the 47X type now as supply of the originals has run out....

[phildu31]

Order a piston kit with rings included : 99999-02108.
That is the replacement reference for front pistons.
They are still available at Yamaha at a very nice price.
And you can mount them on the rear cylinders with no problem.

[steveho]

FYI, The piston and ring kit now offered comprises of a TZR125 piston and the 3XC rings, not the original 47X type. No issue, but should be aware.

[silverstrom]

99999-02108 is for std bore 56.40. A first gen TZR part. I have used them in TZRs here. It will come with a piston and a set of rings. You need to order the Yamaha piston pin and Yamaha retaining clips separately.

You can use that kit for all 4 RZ500 cylinders. Others here have done so.

[Jeff B]

Thanks guys. I had a head gasket leak that smoked the rings on one cylinder. The piston looks good yet. I ordered the correct rings already. It’s frustrating. I can’t find time to work on the bike so I took a day of vacation. The first thing I tried to install was wrong. At least it’s a beautiful day to go for an, um, walk. I so wanted to smoke up the neighborhood!