Premature ring wear?

[gasgasman]

Couple weeks ago, my bike was hard to start. It felt like the compression was low.
Friday night I ran a compression test and it was 90psi.
Threw some rings in it and it came up to 150psi-this was before I started the bike.

Seems like I'm having to put rings in it every 4 months or so.
The last tear down, there was .040 ring end gap clearance. The cylinder measured out ok and the hash marks were still visible on the cylinder.

Last night when I took the cylinder off, the power valve was very dry and the pivot pins actually have rust on them.
I'm using Motorex oil and race fuel.
I wonder if that's my problem? There are no signs of dirt ingestion at all.


I did pull a bone head move while removing the cylinder. I was rushing (had to ride in the am) and pulled up on the power valve rod, which dislodged the actuator balls. So I had to pull the side cover off and fix it.