Jim,

If you get static about the insulator from your local repair shop, you can order it from Dave Carr. His is already bored out for the bigger carb.

Some of the local shops get real uppitty about selling their parts to some crazy jerk that is going to make an airplane engine out of a string trimmer.

I bought mine at a local shop. But I stopped at another near the Willard flying field and they had to have some number of the trimmer that wasn't the model number? I figured they were nuts and went back to the first dealer and ordered another.

These insulators will work pretty good on a bigger carb even if you do not bore them out according to Dave Carr.

After having two of them, I went back to the original kind and use a belcrank.

The Electric start insulator, when bored out has a very thin place on one side that introduces a vacuum leak.

I never got one from Dave but was talking to him about all this. That's when he started to sell them.

Good luck,

Jim