The best low cost frame I know of that is steel, well built with really good welding is the Hyper beach cruiser 26" wheel available from Walmart, but be aware that regular stock bicycle wheels intended for pedal power will NOT stand up to motorised bike usage and speeds, also the coaster brake designs also heat up and either grenade themselves or seize up and throw you onto the pavement.
https://www.walmart.com/ip/Hyper-26-Men-s-Beach-Cruiser-Bike/299035532
Wheels must be replaced with either good heavy duty spoked rims which others here in the forum change out to or the three spoke street mags I use and have been using quite successfully for 5 years now on my Hyper Beach Cruiser.
Here is my bike with those particular mag wheels.
This is my tutorial on how to build a safe and proper motorised bike.
motoredbikes.com
https://www.walmart.com/ip/Hyper-26-Men-s-Beach-Cruiser-Bike/299035532
Wheels must be replaced with either good heavy duty spoked rims which others here in the forum change out to or the three spoke street mags I use and have been using quite successfully for 5 years now on my Hyper Beach Cruiser.
Here is my bike with those particular mag wheels.
This is my tutorial on how to build a safe and proper motorised bike.

Whats the best bike for a 2 stroke?
Were miles away, but I bet our side of the railroad tracks are pretty similar. Before I found cranbrook in trash, I picked up a 74 schwinn world traveler & a 74-75 schwinn varsity people were throwing away, was going to build 1 of them, but long skinny front forks were scaring me. They can be...
