putting some heavy grease around the throttle shafts ends and where they extend out the side of the carb should show the difference , another way to find a vac. leak is to spray around the carb with carb cleaner with the engine warmed and running and you will see a change in rpm when you hit a leak. less of a mess. I dont want to deminish the good of the color tune , I use mine and I think that it is great , and it lets you see what is happening at upper r p m . and you can varify what you have adjusted the carb to. rich or lean. Come in real handy when trying different needles , you can see the flame in the chamber up to 3000 RPM .

I got the video and it was good, it really helps.

I got the synchrotester and was able to adjust the carbs, not too difficult, it actually runs good.

I just got the car painted, original blue for the 71's, #TB903.

Ill post it once all the pieces are back on and the windows are in.

Thanks for all the help.

Any of you who have used a color tune, how does it work?

Can you adjust both carbs from one plug or do you need to use all six? Is it worth buying one or do without?

I got the video from Ztheropy and it was very helpful. The syncrmeter was fun to use and it worked out well.

Thanks for the feed back in advance.

Originally posted by sapruns

Any of you who have used a color tune, how does it work?

Can you adjust both carbs from one plug or do you need to use all six?

I'm thinking about getting one myself. Surely you'd have to use at least two plugs, one from the front 3 and one from the back 3. If you did all 6 and there was a difference between, say, #1 and #2 I don't see how you could adjust that apart from modifying the intake manifold. However, all cylinders sharing the same carb should have the same mixture.

The colortune is used in the # 2 and @ 5 cyclinder in place of the regular plug. These are the "center" cylinders that are fed by each of the carbs, thus they would have the "ideal" mixture that is being spread to three cylinders. The goal is to get a mixture that is ideal. The "ideal" would burn a certain color. there should be a color chart with the tool.

The thought is there would be a slightly different mixture to the "end" cylinders, the ones that are farther from the carb along the path of the intake runners.

Again, set the colotune/mixture, then the balance/unisyn, then the mixture then the balance. They influence each other somewhat, thus the repetition.

Years ago, we also used a set of wire deals that were bent at 90deg and faced each other.They fit into the top of the carb after removeing the oil cap. As the throttle was opened, you watched the wires to see them move in unisyn as they rode on top of the carb piston. The unisyn air flow does this at idle, but does not show the movement of the carb pistons together under various throttle openings..... whatever.

good luck

Originally posted by Lowell Marx

The "ideal" would burn a certain color. there should be a color chart with the tool.

For any of you that have actually used the colortune, what colors do you have to be able to see, and how close is the variation? I ask because I have a very slight red-green colorblindness. I can see red and green fine, but very light shades of red I can't, and two shades close together that other people can tell apart, I can't. Thanks Mom.

I'm not sure but I suspect the correct mixture results it's a blue flame similar to to what you'd see on a natural gas stovetop. Sometimes with those you'll see mostly blue flame with wisps of yellow/orange. If you can differentiate between those you'll probably be Ok with the colortune.

Thanks for all the input. Ill let you know how it turns out when im done.

You only need one colortune device!

Use on one carb at a time to set mixture. That is to say put in the #2 cylinder, adjust the mixture nut on the bottom of the carb, remove and put in #5 and do the adjust. Then set the idle and balance with the unisyn on the face of the velocity stacks of the carbs. Then use the colortune again to check mixture, etc. etc.

Just a note. I have triple webers and was unable to get the unisyn to register anything at all at idle. Has anyone else had this problem? After adjusting the mixture by ear, I used the colortune to check and was very close to optimal. Victor.

Originally posted by tanny

Just a note. I have triple webers and was unable to get the unisyn to register anything at all at idle. Has anyone else had this problem?

Your unisyn "wheel" is closed all the way and the marker still doesn't float?

Hi guys good topic here. I bought a Unisyn recently and haven't had a chance to use it but I was browsing the Ztherapy site and curious about the SM needles they have.

My current engine setup consists of the following:-

F54 Block

E88 Head (With Larger ZX Valves).

Mild Cam.

Extractors Etc..

Electronic Dizzy.

I get pinging on WIde Open throttle or when i give it a bit of stick depending on a few things and I think the car runs better if the choke is out for higher rev driving.

I was planning on gettin her on the Dyno and having it adjusted properly by an expert but do you think that the SM needles will work provided I tune with the Unisyn?

I haven't got a colortune kit and have no idea where to get one, I guess I'll ask around for that.

Any help appreciated.

Also can anyone stand by Ztherapy there info is impressive but I'm not sure if my carbs need to be rebuilt or not. THey seem ok apart from the issue mentioned above.

Thanks.