I've got an old Evra 190 engine. First generation Ryobi distributed by Hobbico or something like that. Way back in the 80's.

It came with a pulley in front of the prop hub-- and behind the prop. The pulley is notched to accept a piece of rope with a knot in the end. Wrap a length of rope about 3 feet long around the pulley about 5 or 6 wraps and pull it smartly. When the knot reaches the end---- it simply pulls out. If your good, and you pull it pretty hard; it will usually start on the first or second pull.

Maybe you can make a new prop hub thats just 3/8" shorter and put a small pulley in there.

My Evra needs a bit of choking with my finger over the carb. It likes to be a little wet, but not drowned-- where the plug is all soaking with gas. Learned this routine on my particular engine only after much swearing and sweating.

Sometimes these engines can be stubborn. You will find a system that works easily. Just keep at it.

Good luck. They are fun, aren't they?