Find a nut that fits your bolt and then try it on the stud. If it fits both then it’s m7x1Maybe I've got it wrong, as this is not an area of expertise for me. I bought a knock off M7 kit from Amazon. When I ran the stud through a wire coil that had not been inserted it opened up the coil. I compared the result with an M7 bolt which I had in my garage and it went in without opening a gap in the coil. There was an obvious difference between the threads on the bolt and the threads on the stud. The stud is from a French MBK moped, but I think the engine is a Yamaha design. I suppose it is possible that the bolt has a smaller pitch but it looked like 1mm between threads when set against a ruler.
it looked like 1mm between threads when set against a ruler.
Maybe I've got it wrong, as this is not an area of expertise for me. I bought a knock off M7 kit from Amazon. When I ran the stud through a wire coil that had not been inserted it opened up the coil. I compared the result with an M7 bolt which I had in my garage and it went in without opening a gap in the coil. There was an obvious difference between the threads on the bolt and the threads on the stud. The stud is from a French MBK moped, but I think the engine is a Yamaha design. I suppose it is possible that the bolt has a smaller pitch but it looked like 1mm between threads when set against a ruler.
I've never seen a M7 helicoil kit. Not to say they don't exist
I've got one. Suzuki motorbike engines have M7 threads on the rocker cover bolts which screw into the cam caps and cylinder head housing. You would regularly find them stripped.
Bear in mind it's a moped, you could probably hold the head down with zip ties and it would stay on Over thinking comes to mind hereMaybe I've got it wrong, as this is not an area of expertise for me. I bought a knock off M7 kit from Amazon. When I ran the stud through a wire coil that had not been inserted it opened up the coil. I compared the result with an M7 bolt which I had in my garage and it went in without opening a gap in the coil. There was an obvious difference between the threads on the bolt and the threads on the stud. The stud is from a French MBK moped, but I think the engine is a Yamaha design. I suppose it is possible that the bolt has a smaller pitch but it looked like 1mm between threads when set against a ruler.