Sputtering, gets worse when revving

[Andymoor94]

Hi all,

Though I have a good guess at the steps I can take to troubleshoot this, I thought I'd share my issue in hope that there's help if I hit a wall, as well as this being here if anybody has the same issue.

803cc engine, but that shouldn't matter! The engine seems to idle ok when started, but then when the throttle increases, it then starts to sputter and die. Release the throttle and you're left with a struggling idle.

I should say that leads are in correct order/haven't been swapped since purchasing the car, which has been running beautifully. Fuel is fresh, this car has been used on the daily. This drove onto the drive one day without issue, then had this the following day.

Though I don't think this will help, I've already changed the plugs and intend to change leads and points, keeping the originals as spare should that not fix the issue. The symptoms point to a fuel issue, if I'm not mistaken, so I intend to 1: Check the fuel filler for vandalism (sugar), 2: Check the fuel pump functionality, 3: Check carburettor, however this is a brand new area for me.

Here's a video from the engine bay.
https://youtu.be/QcBuyQ0RKxE

EDIT: Added paragraph 3