initial Carb setting

arcturus · Jan 21st, 2020, 14:28

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

blueosprey90 · Jan 21st, 2020, 20:04

Yes 12 flats to start

arcturus · Jan 21st, 2020, 20:06

My grey matter is starting to g

et a bit wobbly

Derek UK · Jan 21st, 2020, 20:08

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

arcturus · Jan 22nd, 2020, 09:52

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.

arcturus · Jan 22nd, 2020, 11:45

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.

Ron Kwas · Jan 22nd, 2020, 12:48

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

Derek UK · Jan 22nd, 2020, 13:11

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/

arcturus · Jan 22nd, 2020, 13:33

Found it.21 on diagram

Ron Kwas · Jan 22nd, 2020, 14:30

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

Jan 21st, 2020, 14:28	#1
arcturus arcturus Last Online: Today 08:17 Join Date: Mar 2006 Location: Sagres Portugal	initial Carb setting How many flats from full in,was it 12? Can't remember. H4 __________________ life's too short to drink bad wine Last edited by arcturus; Jan 21st, 2020 at 16:08.

Jan 21st, 2020, 20:06	#3
arcturus arcturus Last Online: Today 08:17 Join Date: Mar 2006 Location: Sagres Portugal	My grey matter is starting to get a bit wobbly __________________ life's too short to drink bad wine

Jan 22nd, 2020, 09:52	#5
arcturus arcturus Last Online: Today 08:17 Join Date: Mar 2006 Location: Sagres Portugal	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. __________________ life's too short to drink bad wine

Jan 22nd, 2020, 11:45	#6
arcturus arcturus Last Online: Today 08:17 Join Date: Mar 2006 Location: Sagres Portugal	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. __________________ life's too short to drink bad wine

Jan 21st, 2020, 20:04	#2
blueosprey90 Master Member Last Online: Apr 23rd, 2024 15:48 Join Date: May 2017 Location: New Milford, Connecticut	Yes 12 flats to start

Jan 21st, 2020, 20:08	#4
Derek UK VOC Member Last Online: Yesterday 20:59 Join Date: Jul 2006 Location: Chatham	Don't forget, 30 minutes at 2000rpm to run in the cam. Good luck.

Jan 22nd, 2020, 12:48	#7
Ron Kwas Premier Member Last Online: Today 11:51 Join Date: Jul 2007 Location: Connecticut, USA	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

Jan 22nd, 2020, 13:11	#8
Derek UK VOC Member Last Online: Yesterday 20:59 Join Date: Jul 2006 Location: Chatham	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/

Jan 22nd, 2020, 14:30	#10
Ron Kwas Premier Member Last Online: Today 11:51 Join Date: Jul 2007 Location: Connecticut, USA	It does look like washer 21 seals the Jet Assy to the carb body...supported by the fact that it's of malleable copper...

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