Piston Skirt

Well I guess it's not viable if my bars won't fit, don't really want to have to buy new bars to fit it at £100/ bar.

I'm wondering if I can just change the bar studs?

Nope. The bar studs are fixed from the inside of oil tank. Technically it means it would take:

a) custom machining of magnesium crankcase and then making the new bigger sized studs.

b) making a couple spacers (internal dia. = stud dia., external dia. = bar slot width) which is effectively simplified version of bar adapter.

Seems like it's better to check the oil hole position on your bar(s), measure the oiler slot position on the saw, check if Stihl-Husky adapter actually fits your bar(s) and (if YES)... get that adapter & saw & bars together

EDIT: this adapter seems to have ALMOST everything right, except it would need some filing/milling in the middle - CS-501SX has additional screw head between the studs https://performanceoutdoorequipment.com/collections/chainsaw-bars-and-chains/products/cannon-cbw-20040-8mm-bar-adapter

Sounds like a lot to measure with all the adapters On top of that you'll want to be sure the oiler holes are where they have to be.

It's really easier to bolt on another chainsaw to the existing bars.

Yes, just measured - the mounting pins are 8mm, which makes the 8.2mm mount (C1) the most adequate

Also, tensioner hole centers are 28.5mm apart. Minimum distance between the 2 holes is 21.5mm, maximum - 36mm.

Actual tensioner axis offset from center of the bar is 13.5mm

Let me know if this sounds hard to understand - I'll just make a couple pictures then.

It uses the same 041 mount (OREGON) as CS-500 (the only difference is tensioner located in clutch cover).

The rim is "small 7" which means it's 18720 for a 3/8 (OREGON)

Sure, you can look up analogues from other manufacturers based on this info.

Just a curious picture that somehow proves that ECHO 590/600/610/620 chassis (= Shindaiwa 598/600/600SX) in fact had Kioritz serial number:

Well, that same guy I mentioned was given a 620SX for evaluation. Obviously more power at the price of more weight. As he spends all day in the woods, he chose a smaller one - fully equipped it's couple kilos lighter - easier on your back and really nimble when cutting branches. Of course if you intend to work on bigger trees and spend most of the time bucking it - 620 will shave off some time

Runs nice. Comparing to the older CS-500 it has a lot less vibrations on idle. Comparing to the CS-510 it has more power at any revs. My friend uses it daily in the forest since august 2015 - nothing wrong happened except usual forester scratches And yes, as usually it takes few tanks to unleash the full power - it's really noticeable.