CRANK SEAL REPLACEMENT

[NOSHER]

Hi guys
engine now running but spewing oil out of both cans-- only light blue haze from the left but obscuring smoke from the right hand even after 20 mins warm up The more it was revved the more of a smoke cloud from the r/h can and both cans still spraying oil.
General concensus is crank seals gone and r/h prob sucking in gearbox oil as well.SILLY QUESTION to which i probably know the reply----can you replace the seals without splitting the cases>
I read the manual through re disassembly of bottom end but photos and text seem to jump stages and aren`t really that explanetery.
A blog with a series of pics on this subject would be great ---any takers?

[SP_BOTT]

can't remember now, but i don't think you can get the gear off the end of the crank easily, so therefor can't replace the seal, or at least not a diy job, would await the experts though.

[NOSHER]

ok fella thanks for the reply--i hope some clever geezer on here has found a way to do it and lets us know--you never know with a bit of luck it may not be the seals leaking--has anyone used a leak down test kit to confirm this problem??

[jarno]

If there is smoke coming from both sides there is a possibility that the inner seals are leak ( the inner shaft is worn)
In both times you must split the cases.

[NOSHER]

hi jarno thanks for the reply--bit strange this one----i changed the right hand carb(still don`t know why)For a spare i had lying around to see if the engine would start after weeks of possible ignition problems and still no start but now plenty of spark----i gave it one kick and the engine burst into life.
the engine did NOT blow smoke or oil spray previously when it was running until i fitted this r/h carb!!!!!!!!!!!!!!!!!!!!!!!!!!!
tomorrow i will refit the original carb and we will see what we will see(probably through a blue haze!!)

[bsa70]

hi i got the cog off using a sturdy bearing puller from jago, on amazon about 30 quid ,first i punched a straight line from cog to end of shaft using an i letter from letter punches as a reassembling guide,then pulled it off using puller.

[NOSHER]

hi beezer-thanks for the reply--is the cog an interference fit? or is it on a keyway? AND--

did changing the outer seals sort the problem(i`m assuming it was smoking badly?) or not?

[JanBros]

you need to split the cases to change the seal,as the seal has as sort of lip that fits inside a groove in the cases

[NOSHER]

Yes Jarno-- i thought that might be the case(no pun intended!!)i`ve just found a picture of a seal and i can see that it has a raised profile on the outer seal surface obviously there to lock the seals in place under compression.
Lets hope i don`t have to fork out for a crank rebuild and the smoky cans settle down with a little more running at temperature.