701 / 1100 Yamaha Piston Interchangeability Question

[jpswift1]

Does anyone know why these Wiseco pistons have this little hole in the side of them? The part number states that they are for an 1100 triple Waveraider, but they are the same exact pistons Wiseco makes for the 701, EXCEPT for this little hole in the side of it and it's 1 number different compared to the 701 pistons. It seems that most other piston manufacturers use all the same exact pistons/part numbers for the 1100 and 701 engines, except Wiseco. Could I run these 1100 Waveraider pistons in my 701 without any issues? I just don't want to lose any performance on my ported 735 62t/61x that I'm going to put together. Thanks.

 

[Storbeck]

I'm about 95% sure that a 62t 701 top end has those little holes stock also.

Conventional wisdom is that they provide some cooling and extra lubrication to the wrist pin bearing and the piston crown. If that actually works in reality I have no idea.

I would run them, I'm running a pair that have the hole in a 64x based twin right now.

 

[jpswift1]

Thanks for the information. I just wanted to make sure it didn't have anything to do with any of the ports, changing the low end power delivery of the engine.