Mk1 golf won't start and misfiring

Can anyone help me
Hi guys wondering if anyone can help me I've had everything new leads dizzy cap and more, 3 weeks ago I was driving my 5 door and it started to bog down and sound like a dirt bike, proper misfiring.




After crawling the car to a freinds houses black smoke coughing out the exhaust and carb,  it wasn't starting at all,  I've found out the timing belt was very loose at the front facing me and after replacing that it still isn't starting 


Any help would be greatly appreciated or anybody who has some 1.5 or 1.6 engines or heads for sale feel free to give me a pm.