we was out running it to day and the pull start came off and there is a piece missing but i dont know what it is it like a nut i think thanks

Thats the one way bearing, it lets the pull start recoil and not pull the crank, but lets you pull on the crank.

do you know the part number for it thanks

I think its r025 but look here http://shopping.netsuite.com/c.84985...4Pa38Ta38Obxv0

ok thank you i think thats it

is there any other bearing that will work on it

take it to your local hobby shop and see if they have one the same size, they should have one