Atc250r aircooled cylinder question

[George_Doucette]

So I have a 1982 ATC250R that I just bought a cylinder for. The cylinder is from an 83 model, I bought a new wiesco piston for it and a friend told me about drilling holes in the piston to lubricate the exhaust port bridge...my cylinder i got of ebay does not have an exhaust port bridge its just open...wondering if this is something that is stock or something someone did and trailprotrailprotrailprotrailprotrailprotrailpro it up...my only concern is if it did have a bridge now my rings will snagg?

[Yamaha_Rules69]

No, only the 300 Hondaline, and Mugen kits had the exhaust port bridge for these cylinders. No need to drill the holes in the piston for this application, as there is no bridge on a stock 81-84 250r cylinder.

[George_Doucette]

No, only the 300 Hondaline, and Mugen kits had the exhaust port bridge for these cylinders. No need to drill the holes in the piston for this application, as there is no bridge on a stock 81-84 250r cylinder.

thanks a lot man, I figured they didnt but just wanted to make sure...quite happy i don't have to drill any holes in my shinny new piston...does the liquid r's have a bridged exhaust port?

[sx250heath]

I think they do. I plan to build a back up motor from my bike.