To be fair not sure as I haven't used this for a long while as I got a diversion after learning on the rxs about 5 years back. has been in the garage ever since. Started it up a few weeks back as am sellling it but when my dad had it MOT'd about 4 years ago the garage disconnected it saying it was damaged and I have never had the chance to look into it. Seem to remember disconnecting the pump when I fitted a new accelerator able at some point which may have done something. Maybe it just needs setting up again properly.
thanks for the advice on the oil mix