I have a Weed Eater 21 that looks just like the picture. It has a side carb. I saw it sticking up out of a trash can along side the road. I have two others that are still being used as originally intended.

I took some pliers and broke the fins off the flywheel. Then I cut the rest of the fins off with a die grinder and carbide cutter. I balanced it on a Robart High Point Balancer. It looks neat enough.

I used a hub and rear mount from Carr Precision. I used a Homelite 25 carb on it.

IDC (Ryobi) Now a part of MTD has engines in many different brands of weed whackers. Most of them are the rear carb variety.

My Ryobi airplane engine began life as a Lawn Boy for its first 15 yrs.

Enjoy,

Jim