** update **
the annoying issues continue - so the fuel issue was down to a blockage in the jet. all sorted.
got it back together and it ran well, and after another mixture and timing setup, i had it running lovely.
I did notice however that it developed a really high pitch squeaking. I suspected an air leak and was correct. The manifold was cross threaded so couldn't tighten up the carb properly. Replaced this no problems. When doing this i noted that one of the gaskets between the carb and the manifold was incorrect, it was for a HS2, narrower hole than the HS4 - I'm sure that didn't help! Anyway i put in all new and correct ones.
Once again, gave it a a little tweak and away we went, really good driving.
EXCEPT, the symptoms are now as follows:
1. Accelerating we have constant smooth power, with no flat spots and good performance.
2. However, when you come off the pedal, the revs drop smoothly but then stick at around 2000, then drop again down to idle.
3. When cursing in say 3rd or 4th - at around 2000, it isn't happy, a bit lumpy/juddery.
4. as soon as you give a tiny bit of gas it picks up lovely, no probs.
5. After use, the car STINKS of petrol but i see no signs of leakage whatsoever, but it hums, most seems to come from the crankcase breather (should i blank or connect to carb?)
6. If i press the crab piston lifter, the revs die off instantly (meaning its too weak usually?!) but this doesn't correlate with other symptoms
7. also the idle is a little up and down - say between 900-1100 - again like an air leak but i have checked everywhere for any leak and can't see.
Any help, much appreciated as always :)
Nick
Edited by SuperDeLuxeNick, 04 June 2020 - 07:13 PM.