I had drained the OEM fork oil out this past November and had simply replaced it with Motorex 2.5 WT and all winter, with the rebound and compression set at full hard and fastest rebound, and then this past spring and now the summer with the adjusters turned to my liking, the forks have been just great as like the true hardcore dirt warrior that I am, I am not picky when it comes to the suspension, as long as it goes up and down and gets me down the trail, I'm good.
So last fall/winter, I simply dumped out and refilled the forks. Some had mentioned I should have at least swished some diesel/kerosene in, or even ATF to give the forks a little bit of help with the flushing of the crap on the inside so this time I will pour in some of the old ATF I have leftover from my CR500R days and ATF was the go-to for cheap fork oil.
I have some Redline 2.5WT fork oil that was on sale for really cheap so I got 4 pints and one of these days, now that it won't be hot and humid and more spring or even fall-like, getting the forks off, drained, flushed, filled and back on the bike will be an easy affair.
I love the suspension on this Beta and I'll be loving it even more once I get new fluid in the forks.