Help with part list for engine rebuild

[Uber_Beluga]

Hi,

going to take on the full rebuild soon and I want to order all my parts ahead of time. This is the list I have so far:

• "Main bearings" (Yamaha DT125R Crankshaft Main Bearing And Seal Kit http://www.pjme.co.uk/acatalog/Yamaha_DT125R_Engine_Parts_Bott.html)

• "Gaskets" (Yamaha DT125R Full Gasket Set Athena http://www.pjme.co.uk/acatalog/Yamaha_DT125R_Engine_Parts_Bott.html)

• "Gasket sealent" (http://www.ebay.co.uk/itm/LOCTITE-515-Anaerobic-flange-GASKET-sealant-GLUE-50-ML-B-B-04-2018/261831854946)

• "various Gearbox bearings" (As detailed here https://dt125r.co.uk/topic/14/gearbox-bearings)

• "Crankshaft rebuild service with new conrod"(http://www.pjme.co.uk/acatalog/Yamaha-DT125R-Crank-Shaft-Rebuilding-Service-.html)

Should I be buying a new Piston? Or only if it looks visibly damaged when I take it apart?
Do I need to do anything differently or buy any special parts considering I have the athena 170 kit?

[Calum]

You will need Athenas 170 big bore gasket set.

[Jens Eskildsen]

And you need to meassure the piston and cylinder for wear, you cant see if fx the cylinder is out of round. Also meassure ring-gap.