Just contemplating starting another build but this time i want to go bike engine so i can have flappy paddles

I dont have masses of money to spend on parts so what engine would you suggest on a budget i dont mind having to clean it up but would like something complete and running witb ecu's and tb's

How about a Fazer 1000,

Old ZX10 or ZZR 1100 - don't have to worry about a CAT with a amateur build with either of those as you are quite safe with an early engine!

Zx9r? I've got a cracking little engine and loom for sale £550

Bandit 1200?

On a mid budget how about the aprilia rsvr twin?