Edelbrock 4025 Uni-Syn Carburetor Balancing Instrument

The unit arrived exactly as described in the Edelbrock 4025 picture. I received it today and was already successful in syncing my 2 carbs (34 PDSIT2/3) on my 72' VW bus. It lacks the build quality of my original English one that I had in the 80's but it works just as well. The manometer tube is plastic within the cast metal (zinc?) column. Obviously the column needs to be folded up vertical when in use. It folds down nicely for storing back in it's cheap paper box and bubble wrap.

works well. good quality.

Perfecto

This Uni-Syn was exactly as described, the photo is exactly as it came. The reason I am giving it 4 stars is that it does not say Edelbrock anywhere on the device and the instructions look like a photo copy of an old instruction.ProsWorked very well to balance my Datsun 240z carbsSeems to be well madeGood priceAmazed that I could still find thisVery compactEasy to AdjustConsThere is no numbers on the float tubeMade in Taiwan (Expected American made Edelbrock)The float seems a bit cheap but it does what it should

This works well on my ‘68 mgb gt. You do have to let the choke cable mount hang for it to work though. Either way pretty self explanatory.

Instructions were super simple. It helped me tune my VW carb quickly and easily.

What a great tool had a great price thank you Amazon for offering this what a great tool had a great price thank you Amazon for offering this tool

Tried to balance the HS2 carbs on my 1275cc MG Midget with this device. Could not get the indicator to lift at all at under 1500rpm, which is a useless situation for balancing purposes. I had closed the venturi to minimum aperture first!The build quality is very poor with several airgaps (leaks) in the indicator tube assembly: 1. Mould flashing in the swivel joint which prevents the joint sealing properly. 2. The top segment of the indicator arm which connects the vacuum passage to the glass indicator tube, has a seal to the glass but nothing to the passage. Tightening up the holding screws doesn't help as daylight can still be seen between the two components.Having de-burred and lapped the swivel joint and installed a soft gasket at the top of the indicator tube, the indicator will now just rise at about 1100rpm but not at tickover - 800rpm.Sent an Email to Edelbrock for advice, but they have not had the courtesy to respond.Overall I am very disappointed with this device, as its principle of operation is elegant in its simplicity and it should work, if it were designed and constructed correctly for small carburettors.