38 replies to this topic

[bigcaddy]

I took my pots off and there is no color on the springs at all. Those are the spirings you mean right?

[jaydee]

Colour disappear overtime.
The spring are recognisable by the number of coils though.
Blue spring, 2.5oz, has more than 30 coils while the red spring, 4.5oz, has about 25 coils.

[bigcaddy]

I will check tonight.

If I were to need new needles to flow more at cruising what would be the next needles up from the AACs?

remember these are spring loaded needles.

THanks by the way.

Tom

[carbon]

Recognising the spring weigh by number of coils is not simple - if only.

I've come across 'red weight' springs with 36 coils, and 'blue weight' springs with 24 coils or less.

The only way of being sure of which spring you have is checking the weight at specified length. Blue is meant to be 71 grams at 67mm, and red is meant to be 127 grams at 67mm. At least that's what is specified in the SU catalogue...

Also if you check the weights then you will know if they are closely matched.

[bigcaddy]

ok. I'll get out my scale. good info

But if I end up having to go a larger needle for cruising what is suggested?

[bigcaddy]

I think I have green ones. I'm gonna pull the other and check. There is a tiny spec of paint on the bottom and the wife and I both agreed (for once) that it was green.. dark green.

[bigcaddy]

They look like green ones. Seems like a bit much

What the heck are green ones from? A Sherman tank?

[jaydee]

The green is is too heavy at 12oz and also i dont think tey're suitable for HS2s but for bigger carbs so i really think yours cant be a green or has been totally mismatched.
The weight that Carbon refers at is the compression rate of the spring, so be carefull when taking measurement.
Swap the springs for some proper red springs at first, then you could start thinking about a different needle..

[bigcaddy]

I already have them ordered. seems logical that this may help fix the issue.

[bigcaddy]

[bigcaddy]

the top portion of the spring and a little on the bottom. I know I need a manicure.

[jaydee]

Yes it looks like a green one 12oz carb spring..

[bigcaddy]

I just checked with the guy I got them from. he said they were on a mini.

Do you think this could be a main part of my issue of hesitating and running lean while cruising?

It seems to me the heavier springs would require more engine vacuum to raise the needles.

[jaydee]

Yes and you dont need them to be that heavy and i've never seen green springs on a mini, thats exotic stuff and not a good idea as its limiting the ammount of mixture affecting performance.
Blue or red on the twins and red or yellow on the hif.

[cooperrodeo]

I had difficulty balancing my twin HS2s, though these were not the spring loaded needle types. It turned out that one of the needles had been misaligned and had worn itself and its jet, such that the jet had to be wound up much higher compared with the one in the other carb in order to get the mixture correct at tickover.

I mention this because it seems to me that the spring-loaded needles were designed to wear themselves and their jets. If you have acquired old carbs, you cannot assume the jets and needles are in good condition.

On HS2s, you do not want springs which are heavier than the standard red. You only fit heavier springs to stop the piston from wanting to rise above its maximum position at wide open throttle and if this is the case then the car is under-carbed.