HS40 Oversized Piston Orientation

[hotshoe63]

Can anyone tell me which direction to install an oversized piston In a Tecumseh HS40 engine? The top of the piston has .010 stamped on the outer edge but no arrow like the stock piston. Wondering if the .010 goes towards the valves or the front the the block?

 

[markus]

HS40 pistons are non directional/centered pin, HS50 pistons (early large bore) and most every other piston 2.8" and larger in the Tecumseh lineup however have an offset pin and the arrow needs to point to the valves so they are orientated properly

 

[hotshoe63]

Very good, thanks Marcus. I put it in both directions beforehand and it seemed to work either way, however the manual stated the arrow should point towards the valves. The engine is for my Blackwidow minibike. Using the original block bored over. Added a billet connecting road and oversized exhaust valve as the guides were worn. it‘s ready to go back together.