Have a 400ex that is now using an excessive amount of oil. It's on the end of the dipstick, from near full, after just one full tank of gas. It's definately burning the oil as it's smoking a bit.

Thinking of just tearing it apart and sending the cylinder off but before I did, was curious if you guys' ex's use any oil at all.

BTW, got a couple of questions too.

What is done to make it a 416 that I've seen some talk about? Larger bore and/or what?

What about the 440?

Thanks.

 

just a note but it could be valve seal and not the rings. i know some brands of oils tend to burn easier in the 400ex's. i have good luck with mobil 1 15w-50.