Synchronize Twin SU Carbs on Series 3 R6

[BRaats]

Evening, I want to synchronize the air intake on my SU carbs, but needs a airflow meter also known as a Uni-Syn meter / gauge.

Any one selling it or know where I can buy it?

I am based in Pretoria.

[Estee]

Gunson make a carb balancer as well as the colour tune tool.

They are represented in SA by Wingate Motors:

https://www.wingate.web.za/gunson-workshop-tools/

If you type gunson carb balancer into goggle you will get a number of alternatives such as bangood at R688.88

Here is a quick video of the Gunson kit

https://www.youtube.com/watch?v=LyUek-lAN5o

[RoelfleRoux]

$34.00 - that's ZAR500.00!
Have you tried listening through a short piece of garden hose?
The colour tune is a nice piece of kit and there isn't really a suitable and cheap MacGyver to substitute.

[Thys Willemse]

Colour Tune is intended to set the air fuel mixture, not balance the carbs. I used the balancing kit on my then Datsun 1200 GX Coupe, it worked perfectly.

Unfortunately I lost the float and reverted to a small pop rivet, I worked as you don't work with calibrated values, just reference points.

[Pieterk]

Do yourself a favour and speak to your local spares shop. They may have a cheaper alternative. I have a cheap balancer, which I bought many moons ago, and it has been doing good service. It consists of an adjustable plug for the carb inlet with a pipe and a gauge with a little float indicating the vacuum drawn. Double carb vehicles are not common anymore and could well disappear altogether. It is not something which is used often. Once those carbs are adjusted correctly, what else would you use it for?

[RoelfleRoux]

Colour Tune is intended to set the air fuel mixture, not balance the carbs. I used the balancing kit on my then Datsun 1200 GX Coupe, it worked perfectly
.

Correct, but unless you do both balance and tune, the job is never done. I learnt on an Austin 1100 (with twin SUs) and later on a Datsun 1600 SSS.

[duncang]

We had a rough set of plastic tubing nailed to a plank on the garage wall. Middle loops filled with a very thin oil.
My memory has gone but someone will know how to make it for 50 bucks?

[Estee]

We had a rough set of plastic tubing nailed to a plank on the garage wall. Middle loops filled with a very thin oil.
My memory has gone but someone will know how to make it for 50 bucks?

Indeed, there are probably plans on YT. But the OP owns a Land Rover with SU carbs so I suspect he will get years of use from a commercial carb balancer and a compact one he can chuck into his jolly box which most LR owners have in the back, in case he needs it on his travels

[Andrepb]

We had a rough set of plastic tubing nailed to a plank on the garage wall. Middle loops filled with a very thin oil.
My memory has gone but someone will know how to make it for 50 bucks?

Believe it or not that’s the most accurate method ( even though the cheapest)
Have a rig like that attached to my garage wall for the several BM “Boxers” I’ve owned over the years.

If you have a “bleed” screw / plug on each inlet on the manifold this method works. Just make sure carbs are close to being in balance when you connect up tubes, else oil ( I use brake fluid ) gets sucked up by carb with highest vacuum.... no damage caused just plenty smoke from exhaust....soon clears

I have a Gunson Carb Balancer kit as well but problem is I’m in Durbs and OP is in PTA.
If you don’t come right send me a pm and maybe we can make a plan to get it to you on loan ( as a rule I don’t sell my tools no matter how seldom they’re used )

Take care and stay safe.

[Dirk]

Maybe speak to the older motorbike mechanics? My Goldwing needed that, and the mechanic had a 4 carb one available (but he works on older and carb bikes).

[duncang]

Think ours had cochineal for colouring ?

[thabogrobler]

I was looking at an old Rolls Royce today and spoke to the 30ish mechanic about balancing the carbs. He recons his father can/could do it almost to perfection with a screwdriver and a 10mm spanner.

[BRaats]

Thank for all the feedback.

I think I will not have a air flow meter on Saturday.
Sometime back I read you can also do it using a plastic pipe.
Anyone knows how it works or a link to an article explaining it perhaps?
Thanks

[Henris]

Easiest for me is to start with the basics.
Make sure the needles are straight and not worn.
Loosen the balance bar so you can adjust each individually.
Adjust the mixture on both the same.
Now start.
Lift each plug lead and get them to affect the idling the same.
Once you have each plug lead to affect the idling equally, you should have the cabs running the same.
Now pick up the balance bar to actuate both carbs equally.

PS. Make sure your plugs are good and the gaps are set equally.

[ghouwens]

[BRaats]

Thanks for the explanation.

Based on the videos I looked at, they adjust the air intake on idle speed before starting with the mixture.

The rest sounds easy.

And at the end, they adjust the idling speed and adjust air intake on +/-1600 revs.

Easiest for me is to start with the basics.
Make sure the needles are straight and not worn.
Loosen the balance bar so you can adjust each individually.
Adjust the mixture on both the same.
Now start.
Lift each plug lead and get them to affect the idling the same.
Once you have each plug lead to affect the idling equally, you should have the cabs running the same.
Now pick up the blance bar to actuate both carbs equaly.

PS. Make sure your plugs are good and the gaps are set equally.

[BRaats]

Thanks

[stephenplumb]

I had an R6 and I did have access to a carb balancer at the time, but a straw or pipe put into the throat of the carb will give you pretty good results. You just listen for both carbs making the same slurping noise.

I eventually chucked the R6 motor and put a Nissan LD28 in there and it was running great guns when I sold it.

[GaryFrank]

Get a decent vacuum gauge and you can set your timing with it as well......old school mechanics don’t use timing lights.

[RoelfleRoux]

Get a decent vacuum gauge and you can set your timing with it as well......old school mechanics don’t use timing lights.

Please explain... honest question.