initial Carb setting
 

How many flats from full in,was it 12? Can't remember. H4

Yes 12 flats to start

My grey matter is starting to g:regular_smile:et a bit wobbly

Don't forget, 30 minutes at 2000rpm to run in the cam. Good luck.

Been having problems with carbs dripping fuel and on inspection have noticed that the copper washers 17. on parts manual between carb body and upper bushing 16. are missing.Could this be the cause? I have noticed that when adjusting flats that sometimes the whole bushing turns and there is no adjustment.

Everything on hold now.One of the little dished brass washers which sits between the bushing spring and cork washer dropped of and has disappeared somewhere into the dark corners of the garage! Ordered replacement and aforementioned bushing washers.

Arcturus; In general, malleable copper washers are used for sealing, but without seeing precisely where (17) is located in the assembly, I can't wager a guess as to function and if it might be cause of your leak. Can you give link to or post Exploded Assy Diagram showing this Ref No.

BO90; ...are you certain?...I recall seeing in another recent thread, starting Jet height for H4 as different from HS6, (which I agree is 2 turns/12 flats down)...don't know thread or H4 value given there, sorry...

Cheers

For HS4 a bit of Googling brings up 9-12 flats. For this start up 12 should be fine even if in the end it turns out to be a rather rich setting. You can correct that later. This initial start will probably be helped by a slightly rich setting is what I'm saying. Critical is that the needle is properly centred before start up to make sure the pistons rise and fall with no obstruction.
https://www.mgexp.com/article/su-tune.html
This article goes into setting the jet height using a depth gauge. Much more precise and if you have a long enough probe on your vernier you can give it a try. Probably best done on the bench initially.
https://www.mgexp.com/forum/mgb-and-...tting.2796944/

Found it.21 on diagram

It does look like washer 21 seals the Jet Assy to the carb body...supported by the fact that it's of malleable copper...