Carb balancing

[PaulBSpit1500]

Hi all, 

Getting more and more frustrated trying to tune my 1500 1977 Spitfire, HS4 carbs. Does anyone out there know of a mobile tuning mechanic that could set these up. Car currently in Uxbridge. 
 

Paul 

[dougbgt6]

Well, there's Doug in Twyford. 

db

 

[PaulBSpit1500]

Indeed there is, not sure if I can afford his rates. 😊

[Mathew]

Do you have a carb balancer. If not a keen hearing with a screwdriver for the hiss. Dont forget to loosen the linkages otherwise you will be working against yourself.

[Mathew]

Colour of number 1/2 plugs and 3/4 plugs

[Pete Lewis]

just set the idle stops from just touching  and wind in 1.5 turns    that sets both throttle plates in the same position   thats how they went to the factory 

no faffing around  just get them in the same mechanical setting 

do the same with mixture  level the jet with the bridge and turn down 3 turns 

adjust equally to get a nice idle .. job done

do you have wax stats on your jets    ...they can really mess up , prise the cap off the bottom remove the wax capsule dont loose the small steel spacer its needed 

add 2x 1p pennies and refit the cap/crimp 

 

or see Doug and buy him a beer 

Pete

[sulzerman]

Hi Paul I have got a Synchrometer excellent piece of kit.

I have balanced my carbs perfectly with this. Well made and simple to use

https://www.amazon.co.uk/STE-Synchrometer-Weber-Dellorto-SYN001/dp/B00DHGX2D6/ref=pd_vtp_1?pd_rd_w=wU3zj&pf_rd_p=75613b4d-6e08-4583-9b7e-f6e766dc0b40&pf_rd_r=N34B559HGK28SJ2N4JZB&pd_rd_r=5f5637ed-dab9-4f4c-a011-6e745c3a6d9b&pd_rd_wg=O1qQa&pd_rd_i=B00DHGX2D6&psc=1

Hope this helps

All the best

[Anglefire]

I have one of those too - and it does work extremely well  

[AndyTV8]

15 minutes ago, Anglefire said:

I have one of those too - and it does work extremely well  

Ditto, finally picked up one of these last year - wish I’d done it years ago! 

....... Andy 

[sulzerman]

4 minutes ago, AndyTV8 said:

Ditto, finally picked up one of these last year - wish I’d done it years ago! 

....... Andy 

Superb tool, far better than the Gunson effort!

[johny]

hey for 40 years my Gunson has served me very well - I cant see you need anything more unless youre running a business!

[Anglefire]

If I could have found my gunson one, I'd have tried that (Bought sometime around 1990 when I had a P6b) but no where to be found, so bought the Synchrometer 😀

[Colin Lindsay]

I bought one of these, many years ago, for the Spitfire.... this just reminded me that it's been hanging on the wall for years. Had to blow the dust off...

  

 

[Pete Lewis]

ive had one of these for years

 

 

 

but setting to a simple and fairly accurate mechanical pre setting 

does all you really need ,just the way they were set before fitting to the engine on the assy line 

balancing to extremes is a faffing about myth  as soon as you open the throttles   you loose the idle setting you have been worrying about 

so back to set the throttle plates to the same setting set the mixtures to the same setting and you have a balance so you can equally adjust from that 

yes leaky spindles etc will have a bearing on idle air flows but thats a different problem that needs solving 

Pete

[dougbgt6]

That's the same as mine! Got it on Ebay for a fiver.

Doug

[Steve P]

1 hour ago, Colin Lindsay said:

I bought one of these, many years ago, for the Spitfire.... this just reminded me that it's been hanging on the wall for years. Had to blow the dust off...

  

 

That`s what i have,bought years ago from e bay,i like old school stuff..

S

[JohnD]

Colin,

How is the rubber on the face of your Synchrocheck?    Mine feels like rock, and I have to press it really hard to get it to seal.

Possible to cut off and replace with new rubber?

[Colin Lindsay]

It isn't great, John... very hard and incredibly difficult to get a good seal, but then I found out I might be missing the cone that fits into the carb mouth... which I didn't know about until I searched for these on the Net last night. Mine just has a flat rubber circle. I wonder if they're available as a replacement item, even very old stock?

 

 

[Pete Lewis]

the trouble with any flat rubber seal is it can and does cover the front face ports and that messes it all up

mines flat but ive cut a air bleed relief in the rubber that covers the ports in the front flange

Pete

[Steve P]

Mine has the flat rubber disc,then the image below which has a lip on the back and fits over the flat disc.

Steve

 

[johny]

The Gunson comes ready made with a cone that seals with the lightest touch😜

[Steve P]

Yes but it`s not old..maybe Colin could butcher a Gunson unit for the cone.

S

[johny]

Not old? Must be best part of 40 years old! Possibly could use the cone on other flow meters I suppose...

[PaulBSpit1500]

Thanks for the  advice guys. Pete penny mod done. New needles installed. Mathew flow meter used as shown. Plugs sooty. Off for one last try using your advice, maybe I’m just being fussy. 

[Pete Lewis]

you did replace /keep the small steel spacer that  sits in the wax capule   needs to fit  between 2p and the jet base 

or the jet is going to be far too  low / rich by miles 

Pete