Got a message back from k-tech about their recommendation.Good quality 10w oil with 145mm air gap.
a litre will be plenty
Bringing up a dead post here, but in the name of "sharing is caring".If you want 7.5w oil that will last almost forever, and look after your forks. Buy an atf dexron 6 (vi). It's quite rare in the UK, but valvoline maxlife atf is pretty available.When you bare in mind that a fork oil is essentially a hydraulic oil. That's is. Some have anti foam and anti wear additives, but they're all rubbish. Atf is a hydraulic oil, gearbox lubricant, seal conditioner, anti corrosion etc. Dexron 6 is a spec that requires a drain interval of 100,000 miles normal driving, and 50,000 miles "severe use".We all know how disgusting fork oil gets after a long period of time, but I've used it on my enduro bike for 2 years now, and it comes out looking almost identical to how it goes in.Only reason I'm plugging the valvoline is because it's the only atf dexron 6 I've found in the UK. And it's viscosity falls right in the 7.5wt region which is perfect for the fazer and correct for the marzocchi forks on my crosser.Have a look at this link and see just how rubbish most fork oils are, and how some manufacturers use literally the same oil for 3 oil weights... http://mahonkin.com/~milktree/motorcycles/fork-oil.html