9 replies to this topic

[jpw1275]

hi all.... got a set of fixed needle hs4's..... im running a pretty much standard 1275cc ... are the needles the same has hs2's.... so would a set of gy needles be a good starting point

cheers james

[jpw1275]

on inspection they have swinging needles.... are swinging needles better than fixed needles?

cheers james

Edited by jpw1275, 26 October 2013 - 11:01 AM.

[rally515]

Id say yes.......because i flipped a coin and it said so

[jpw1275]

cheers cliff....lol

[rally515]

You're welcome J , just speaking from my experiences like....  

[carbon]

GY profile needles are likely to run weak on 1275 with twin HS4s using blue springs, might just work with the heavier red damper springs. Will need setting up on a rolling road as air filter, cam, and exhaust type will all have effect on mixture strength. Running weak won't do your motor any favours - does not take long to burn out an exhaust valve with weak mixture and hard use.

 

Worth checking what needles you have currently fitted in your twin HS4s. Main downside of running swing needles is that they rub against the jet and tend to wear at the idle point (makes setting up the idle mixture tricky).

 

Not sure if you will see much benefit from twin HS4s on a 1275 in 'standard' tune over twin HS2s or even a single HS4 on a good manifold.

[jpw1275]

cheers carbon..... is there a way to change to fix needles? at the moment they have aau needles in, i was told they came off a 1380 but cant clarify that.... only using the hs4's as i got em cheap as chips.... i have several sets of hs2's and this set on ebay at the mo... item number 321234267691.....think ive got another 3 sets in various states ...:0)..... also using the hs4's incase i upgrade cam etc once i remove the engine

cheers james

[carbon]

To change a HS4 with swing needle dashpot to a fixed needle version would be a real faff. Much easier the other way round...

[jpw1275]

Ah no worries il just stick with em..... Are the aau needles ok for a 1275 just to get me started? And maybe a 30 mile trip to a rolling road once the car is ready

Cheers James

[Vipernoir]

Burlen sell an insert to allow fitment of either fixed or swinging needles.
ABF193 is the part number I think and they're only a few quid.

 

You can also fit the flanged end bit from a swinging needle onto a fixed needle to make it into a swinging needle.
Steve Harris made a pair of number 5s into swinging needles for my wife's car that way.