Hi everyone. I’m running a 1600 xflow engine in a circa 1975 ford watermota engine on my boat. 
I need some help identifying a missing / broken part from the carb. I think it’s called a vent. It’s now just a hole where it used to be. See photo. 
Also 2 things from your knowledge. 
1. Problem I’m having is not firing but spitting back through carb. Could this missing part cause a very weak mixture?

2. Where can I source a replacement part. 
 

Thanks in advance. 

2 hours ago, David stannard said:

2. Where can I source a replacement part. 

Complete carburettors of this type can be found on eBay for around £60

The missing part if I remember correctly was for attaching the fuel vent pipe.

Yep, vent pipe, just fit any union that fits with a piece of pipe on that points down, water will be getting into the fuel bowl.

Or sell the engine, it's worth more than your boat😉

Thanks for the info. And yes, most things are worth more than my old boat😂

I have stripped the carb but there are 2 issues. 

1. There should be a discharge ball and weight. I have 2 balls and no weight. I’m thinking that as these weights don’t seem to be available, someone has put an extra ball in to act as a weight. 
How would this affect the operation of the carb? Bear in mind we’re not dealing with performance here. 4mph at about 1300 revs. 

2.  On taking the accelerator pump apart, there was a washer inside the housing. Black sort of rubber on one side. It looks purpose made, but all diagrams I see of this carb do not have this washer.  See photos

Any help appreciated.