Question? Mounting Sprocket to a coasterbrake hub

Hi from a newbie,
I am new to the forum and just ran into a problem with the first step of my first build!!! Hope I am in the right forum and am not repeating a tread. I have a 1957 Schwinn Corvette 2 bar Cantilevered Beach Cruiser. I purchased aftermarket "China" Chrome wheels with 26 x 2.125 WW. When I installed the sprocket from my 80cc Raw Kit on the rear wheel , the hub "cog" (if that is what it's called) does not stick out far enough past the sprocket to reattach the coaster brake arm. I know the arm will hit the mounting bolts of the sprocket but I know how to bend it to clear...except I can't even slip the arm on on the axle. I called the kit dealer...he said buy a hand brake!! Suggestions? Any other obvious problem I will encounter trying to motorize this bike?
Thanks for any help
Jim
Indian Wells Ca
P.S. Since I'm new I have added a picture of my bike I want to motorize...and for fun another 1957 Schwinn Corvette I purchased when I was 12 years old and just finished restoring.

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Nice looking bikes! The one built in 57 is the same age as I am, but the bike seems to have aged better than I did.
I don't know too much about coaster brakes but I will tell you that you do need good brakes on a motorized bike and front and rear and the pull brakes would be a good idea.
If your trying to stay original you could look on ebay for some of the older brake systems. Some even used a metal rod, instead of cables and have that cool old Indian motorcycle look.

That "dealer" is an idiot....

You can grind off the outer flange of the dust cover, or grind out the center of the sprocket to fit.

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If it ain't broke, and you mess with it long enough, it will be.

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If it ain't broke, and you mess with it long enough, it will be.

Wow!
You folks are very fast and very knowledgable. I will give it a try.
Thank you!

I machined the center of the HT sprocket to fit over the Komet brake and didn't have any problem.