Vacuum gauges????

Hi Karl, I think you're right by saying that no-one wasted their money on fancy stuff! A vacuum guage, or even better,twin vacuum gauges, would work fine. I've only used them on cars - in particular Jaguars like the E-type and Mk10 which each had 3 carbs! All the other Jags only had 2. I found that setting them by ear was just as good in the day, but not now as my hearing is poor. I've seen twin and triple gauges at bike and car shows and you'll probably find them on the internet.

The problem is they will tell you nothing about the mixture at any rev range as they only measure the suction of the intake. If you have an inlet balance pipe you'd need to block it off if you're only using a single gauge as the readings won't be true. The good old Colortune works for judging actual mixtures of each cylinder. I've had mine for over 30 years and it works on any petrol engine. The only adjustment on Amals is the throttle settings sothey're used to balance them. Used with a Colortune you can get it spot on.

The Haycraft's Norton book instruction about how to set up twin carbs is pretty good. It involves getting the engine warm, stopping it and removing a spark plug and lead to set up a very slow tickover using the throttle cable and air screw. You repeat this with the other cylinder then use both plugs and adjust the throttles equally to get the right tickover. Not as good as gauges though!

Cheers, Lionel

Hi Karl,

I've been using a set of "Morgan Carb balancers" for years, they are excellent and take the guessing out of the job. Setting by ear is for dinosoars and we know what happened to them. You might as well set your timing with a fag paper at the same time! I bought a set of four cylinder ones so I can set any modern bikes as well. That and a good strobe will solve a lot of running problems. Xmas is coming, treat yourself. give you an excuse to get out in the garage on Boxing Day, you know you want to.

Previously wrote:

Hi Karl,

I've been using a set of "Morgan Carb balancers" for years, they are excellent and take the guessing out of the job. Setting by ear is for dinosoars and we know what happened to them. You might as well set your timing with a fag paper at the same time! I bought a set of four cylinder ones so I can set any modern bikes as well. That and a good strobe will solve a lot of running problems. Xmas is coming, treat yourself. give you an excuse to get out in the garage on Boxing Day, you know you want to.

wats rong wiff fag papers??

Previously wrote:

Hi Karl,

I've been using a set of "Morgan Carb balancers" for years, they are excellent and take the guessing out of the job. Setting by ear is for dinosoars and we know what happened to them. You might as well set your timing with a fag paper at the same time! I bought a set of four cylinder ones so I can set any modern bikes as well. That and a good strobe will solve a lot of running problems. Xmas is coming, treat yourself. give you an excuse to get out in the garage on Boxing Day, you know you want to.

Hi David, I bought a set of Morgan carb balancers a few weeks ago and had a go on my 850 Mk2A. I removed the rubber ballance pipe between the two curved inlet tracts and plugged 2 of the pipes from the carbtune into the little metal stubs that the balance pipe goes onto. I could not get very satisfactory results. One collumn was showing a reading but the other wasnt so I adjusted the throttle cable on that carb and watched the gauges, still nothing...... I kept on adjusting the cable on the non reading side until the bike was revving its head off but still no reading on that side. I even swapped the pipes over to make sure it wasnt a faulty gauge but the non reading transferred over to the oposite collumn. Am I doing it wrong ! shouldI not be using the inlet tract take-off. How do you do yours. The fault isnt a blocked inlet tract port as you can blow down the pipe quite easily, Also if you suck the balance pipe attached to the non reading inlet tract you get a mouthful of very unpleasant petrol flavoured vapour..... do not ask me how I know this. !

Cheers Big Alan Clarke, Shenstone Branch

Sounds to me like the carb balancers are faulty. I connect mine to the same balance pipes as you and they indicate correctly. There is a very small bore pipe within another clear pipe in the line and this acts as a damper to stop the rods jumping up and down. If that tiny pipe is blocked then the gauge will not work. I've just been into the garage and if you suck on the black pipe to the gauge it will lift the rod. The small bore "damper" is very small, probably about 0.020" dia.

Previously wrote:

Sounds to me like the carb balancers are faulty. I connect mine to the same balance pipes as you and they indicate correctly. There is a very small bore pipe within another clear pipe in the line and this acts as a damper to stop the rods jumping up and down. If that tiny pipe is blocked then the gauge will not work. I've just been into the garage and if you suck on the black pipe to the gauge it will lift the rod. The small bore "damper" is very small, probably about 0.020" dia.

Hi David, thanks for getting back to me so quickly. I'm sure I put the gauges together properly and fitted the the little damper pipes etc. when I had trouble I too sucked on the pipes and got the rods to lift on all collumns. I've got 2 commandos, the Mk2A and a Mk3. I didn't try the gauges on the Mk3 so if I try them on that bike I might get a different result . The mk2A runs fine and is quite smooth so I dont think there is anything wrong with it, its just that the gauges didnt work right first time, so I thought "Oh another £80 wasted" and went back in the house in disgust.Now you have told me that you use them in exactly the same way thatI didI will give them another try and attempt to get them working properly. It might be something simple like an air leak on the take off tube or something.Wish me luck.

Cheers Big Alan Clarke

For anyone who might be interested in going for carb balancers for their twins, VMCC do them for £75(Twin gauges)inc. VAT & UK postage. They also do balancers up to 6 carbs! PHEW! Three triple-choke Webers on an E-Type?

Cheers, Lionel