I have an 1989 yamaha blaster that I burned a hole in the piston on. I rebuilt the motor (new piston,rings, bored, cleaned and chamfered ports). After, I reassembled the motor it ran good for about a block, and then started to burn gearlube terribly and run just as bad. I have since split the case and cleaned and examined for cracks warpage etc. I didn't find anything wrong with the case halves, so I resealed them using loctite 518 gasket elimnator, which is made for aluminum. I also replace the oil seal and the pto side. But, it stills burns gearlube. I am so confident it is burning gearlube I disconnected the oil injection line and it still smokes terrible. Any help on this problem will be greatly appreciated.

 

Check the crank seals again.Either they are not in properly or the bearings are bad and causing the seals to go bad

'98 banshee

 

Do an pressure test, (not compression) that will tell you if the seals are all in good working order.

YFS200

 

How do you perform a pressure check. I asked my local dealer to do this and they said that they didn't have the tools to do a pressure check.