Hi , just looked up about Timeserts ,they do exist ,they are a different thing to helicoils ,most small size helicoil kits are cheap enough to buy for home use, but in larger sizes i dont think the timesert kit is for the DIY market . ring around your local engineers or garages .You will probably be able to screw the remains if the helicoil back out ,anticlockwise ,with some long nose pliers but try to get it out in one piece ,gently .
i would be suprised if the person who had the helicoil fitted striped down the motor ,therefore there is the possibility that bits of alloy were already in the motor ,the same as will probably happen with the timesert ,but if you ( THEY )drill the pilot hole with plenty of grease on the drill bit and on the tap you will minimise this .
To flush the engine out after fitting try something like parafin , pour plenty in the oil filler hole and allow it to flow out through the oil screen hole hopefully taking any swarf out with it . Do not run ,People can offer alternatives if they can .Not sure if your bike has two screens ,mine did and two oil filters ,but remove all drains and flush through . You also can get flushing oil that you use to clean the engine out ,change the filters a couple of times and drain ,do not ride the bike on flushing oil just run it through . When it`s done take it for a steady run with your fingers crossed .