The manifold is the main part of this conversion.
The 3/4 copper water pipe is a good start as it matches the carbs bore. My gut feeling is the transition from the 21mm bore to the stock manifold accelerates the flow improving throttle response. Fairing this in is a must.
Be interested to see what you come up with.
The pulse port in inside the carbs throat so no case/manifold drilling for a pulse line is required. The nipple on the diaphragm cover is a vent probably went to the saws air filter box. Just leave it open.
Use a small cotter pin to attach the throttle cable to the carbs butterfly. Pop it over the cable stick it thru the hole bend the tangs back and clip em off. Instant swivel. The stock throttle cable works however it has more travel (1/8"). Position the cable bracket so the slack is below the cotter. This has a bit of slop but doesn't over pull the butterfly. Or shorten the cable.
You will spend a bit of time dialing it in. The carb has the ability to choke it or starve it with fuel. It will scream on top end when too lean. Stay on the rich side of this point, or bye bye piston! Work the lo/hi together to get a decent mid range.
This carb has NO throttle stop adjustment. It has a small window in the butterfly for idle speed. Works perfectly with a good idle on the 66cc.
Finally when properly set will take a bit of time to warm up and likes a partial choke.
Hope this works as well for everyone else as it has for me. Feel free to ask any questions