I bought a m6x1.00 kit to fix the reed bolt threads on one of my cylinders. You can get them off of eBay or through timesert. Same price either way. The kit was around $65. You get 5 inserts, the drill, countersink, tap, installation tool, and it all comes in a nice case. If you haven't looked at them, they are a lot better than other options IMO. I'll get a pic up sometime showing the finished cylinder and the kit. I had drilled and tapped 2 holes before I used this kit and had no problems. The previous holes were the idle screws on the stock carbs and finished them just before I started on the reed bolt holes. You'll need a drill, tap wrench, and cutting oil. It's easy.