Need information or help about piston rings

[xavpro13]

Hi everyone! I have a yamaha jt1 1972 and I'm facing a little problem. In fact, one of my piston ring just broke... That may not seem a big problem, but for a rare bike like that it is. I can't find the right ring to replace the broken one. My piston and cylindre is oversized of .50 mm so I need a 42.5 mm ring. I found some, but they are 42.5 x 1.2mm (http://www.hlsproparts.com/Caber-piston-rings-set-42-5mm-x-1-2mm-p/cr42512.htm) and I need a 42.5 x 1.3 mm. I was wondering if it could hurt my engine if I buy one of these and if yes can you help me to find one please I am desperate ...

Thank you for the answer.

 

[ezcome-ezgo]

1/10 of a millimeter? I wouldn't think it could hurt. But I am no expert.

Here you go:
http://www.ebay.com/itm/1971-72-Yam...-STD-/222606958650?fits=Make:Yamaha|Model:JT1

 

[xavpro13]

Yeah this I what I thought, but I am no expert as well ahaha and yeah I found those, but they are the original ones (42mm) and I need oversized ones (42.5mm), but thanks for the help !

 

[bob58o]

I looked for almost a full minute and did not come across one piston ring with 1.3mm thickness. 1.2mm or 1.5mm. Maybe I'll look for another 30 seconds just in case.

 

[OzFab]

1/10 of a millimeter? I wouldn't think it could hurt. But I am no expert.

Inside an engine, tolerances are very small; 0.1mm may not seem like much but, it could mean the difference between lasting years & minutes...

Having said that, xavpro13, is 1.3mm the size of the ring or the ring groove?

 

[xavpro13]

It is the size of the ring itself! Thanks for the answer!

 

[OzFab]

Measure the groove, report back...

For best results, use feeler guages...