After cleaning the varnish off my Carburetor I reinstalled it to the factory specs and stripped the thread on the rear stud torquing it to 10 pound feet. I had three options:
1. Rethread it to 8mm and make a special stud
2. Rethread it to 8mm and use an 8mm stud
3. Use a helicoil and stay with 7mm stud
Since the hole for the helicoil is larger than 8mm I decided to go the first route. Without doing any drilling I ran an 8mm x 1.25 tap into the hole which worked great but I needed a bottoming tap. So I ordered one of those and cleaned up the thread as deep as I could go.
I then took an M8 bolt, filed off the threads and tapped it to 7mm. Unfortunately two attempts could not get the stud true. So I abandoned the first option and moved to the second.
I bought some threaded rod and cut the stud. Made a sleeve for the thread that was perfect from a tire thread depth device I was given. Did a trial assembly and it was fantastic except that the 13mm hex from an 8mm nut could not turn in the space provided by the carb.
After a lengthy search on the internet I found a place that sells 8mm nuts with an 11mm hex so I ordered them. The place is http://www.belmetric.com and I provide this only for convenience – I am not promoting them. There shipping is high for a few nuts.
Once the nuts came in assembly commenced. I used a blue thread lock on the stud in the engine
See the pictures for more details.
All torqued up good. Have run the scoot for a while and no leaks. So far so good.
Now if I could only get it to run well…
