original Invader Crank seals replace or leave alone ?

[sledtillded]

I am in the process of picking up my first Kawasaki Invader 440.  It is an 81 in very good original shape.  My question is do I pull the engine down to do the crank seals right away or leave it alone and run it as is ?  I have been told it is a big job with the gear on the crank.  I have never had a liquid apart but would rather do it right the first time and new crank seals seems like the right think to do.  I know guys that run these engines as is without doing the bottom end and was told to just leave them alone.  if you all recommend doing them please provide any tips or tricks for a complete tear down.
thanks in advance

[Lloyd (ljm)]

  I'll be the first to say it.  Do the crank seals!!
 it is not that bad a job. Use a bearing puller to remove the gear. Set the gear on a light bulb or I use a toaster oven to heat the gear. Then the gear will slide back on the crank.

 If you don't do the seals you will be rebuilding the engine.

 If you have questions there is lots of help on here.

 Lloyd

[gixxer6]

Definitely do the seals.  It's not a question of IF they will fail, it's WHEN will they fail.  And a 30+ year old crank seal is a REALLY old seal! 

Like Lloyd said, use a gear puller and the light bulb trick.  Coffee makers work too, or stick it in an oven.  Make sure you use good sealant on the crank case halfs, it must be rated for gas immersion. 

[JDmatt]

x3, Do it, or you will likely have a blown piston later. 

[sledtillded]

Thanks everyone for the feed back,  I figured as much and will do them for sure.  the gear puller and light bulb trick sounds exactly like what I needed to do it right.
Cant wait to get started !
Cheers