how deep should seals on main bearing be

basicaly the cases i got one of the bearings is bollocksd and ive noticed they dont have the rubber seals in them either so ive ordered a new set and started to have a little read up on installing them and it says i need to measure how deep they were in before...wich i cant do as they arent in so does any one know the correct depth
its an ac 125 new shape engine with a stock crank

 

is there not a lip for the seal to sit against ?? surely if u have to measure it would never be right n e way

 

haynes ses u gota measure it can any 1 else confirm whether or not u gota measure it

 

yes that is correct....

the seal has to be far enough into the case so that it dont pop back out
again from secondary crank case compression, but not so far in that it is actually rubbing on the bearing

 

are there any seals in the cases

 

ok problem is the cases i ws sold with "fresh bearings" that are fucked dont have any seals....so how do i find out how deep they need 2 go?

 

125's sit flush,
the 50's need to be in a certain depth.

all in the manual.

 

ok trouble is im using my old runner haynes manual so i have the option of lookin at the 125 lc engines or the 50 ac engines but thankyou for the info

 

piaggio scooter manual covers typhoon 125,
same lump as yours!

 

bait iv got one ill have a look after iv got ma lacquer bruv

 

alrite bruv need 2 chat 2 u btw say sumin 2 me wen u come on msn if i dont say sumin 2 u cos im half outside half inside