I went with 15g for cruising, plastic kymco cover... I just left mine off, but I have a brand new cover from my kymco with less then 500 miles, if you want it, let me know.
Lots of 10mm bolts, then slowly pry it off or light tap on the cover to get it off. There is a gasket so don't rip it if you don't have to. I use impact wrench to remove the 17mm nut, without it, you need to fab something to hold the face cover or it will rotate when you try to loosen it. People suggest to replace that 17mm nut-one time use.
Putting it back is a little tricky, need to make sure the belt is not interfering with the pulley when tightening the 17mm nut, so I took a long pole skinny pole I had and keep poking it towards the front to wiggle some room to tight the 17mm nut slowly until flesh with the spacer, then I tight it down. Whole job probably took me 15min top.... but then again I installed my own engine, so might be different from you.
slider was purchased from Amazon, cheapest place I can find, $24 I think, but I got the last 15g, they have one last set of 14g at the same price I think.