2.5 hp mercuty problems

[alexedit]

Hi -
this motor is like new but it take a lot of pulls to crank...and then it works for a bit and stalls. - it has a new spark plug

also - what is the gas mixing ration for this motor?
and
where can I find parts for it? is there a place on this or any other website that can help me find the propeller and the propeller pin by putting the serial number?

please help

the serial number is 06854362
the propeler pink broke and i don't know the size of it so that I can replace it -