fellow Minioids,  OK, I went out to the garage tonight.  It went from 47F yesterday to 10F in one today.  One of the twin HS4s is good and drops to the bridge.  The second one falls to about 1/8" from the bridge. The garage is heated to 50F but things have expanded or contracted with this massive temperature shift.  I may be good to go now.  More to come.................

Dogscarf

I have M needles to start with.

Dogscarf

AFAIK all the jets and needles are the same length at least with HS2's and HS4's but as Steve said the larger carbs use a thicker 100 thou jet and needle where the smaller ones use a 90 thou jet and needle.

What needles do you have fitted ?

I have centered the jet bearing and jet without the spring.  I think that what Coopertune wrote may be applicable, different size jets and needles.  I think that the needles are too long for the jets.  I have probably 7-8 HS4 carbs and they are all in good shape, not need to buy a set for $800-$1000.  That is throwing away a lot of beer money.

Dogscarf

I'm not sure if you are doing it this way but when you center the jet you need to do it with out the spring and adjusting nut in place. This applies to fixed needle SU's as swinging needle SU's are self centering.
Which Austin Healey did you get these carbs from? A Sprite would use HS2's and a Healey 3000 used maybe 1 3/4's i thought but i am not sure on that.

dogscarf.. I just buy new carbs now from www.burlen.co.uk   instead of trying to fix old ones..  too much trouble and you can NOT believe   how much better a totally new carbs run on a mini.. later bc

You do realize there are .090 and .100 and even larger needles and jets to match. I like to use the MGB HS4s the linkage is all there just needs adjusting for length. I'm looking at using a set of MGB HIF 38s on a 1400 cc mini. Steve (CTR)

Yes, without needles the piston hits the bridge.  I was wondering if there are different length needles and jets.

Dogscarf

Am I correct assuming that with the needles removed the pistons will drop to the bridge?

These are early carbs off of a 1962 Austin Healey.  They have fixed needles.  It is perplexing to me as to why the pistons do not drop all of the way down to the bridge. 

Dogscarf

Late HS4 carbs used the swinging, spring loaded needles and the jets won't center.  I would start by checking that you haven't mixed early and late parts.  

Fellow Minioids,  I am in the process of fitting a pair of HS4 carbs to my 1967 Cooper S.  I have several carb bodies, flots, dashpots to choose from.  I have lots of extra parts from Austin Healey 3000 projects with triple carbs.  Anyway, I know they used H4 carbs back in the day, but the only pair of those I have is from a Volvo, and I don't like those carbs anyway.  HS4 is what I am using.

The issue that I am having is the piston not coming down all of the way and making contact with the bridge.  I have tried multiple needles, multiple new and old jets, multiple dashpots and piston assemblies, multiple jet assemblies and more.  They all stop about 1/8 to 1/4 inch from the bridge.  If I push them down further they become wedged!!!  I have tried to center the jets several times, I have used other carb bodies as well.  Still an issue.  So, my needles are 1.5 inches long from tip to the shoulder.  My jets are 1.35 inches long from jet tip to where the jet enters the black plastic.  I tried putting the needle into the jet without the carb body and it fits fine????  What gives as soon as I put the parts into the carb body they do not work?  Do I recess the needle past the shoulder into the piston?  Are there longer jets available?

Dogscarf

1967 Cooper S
1965 Cooper
1968 Cooper S