First you will want to get a wooden yardstick from your local hardware store. It will look something like these...


This is what you will use as the base for your manometer.

Next you will need about 35' of clear plastic vinyl tubing. You want 1/4 " to make your manometer. The 1/4" inch size refers to the I.D. of the tubing.



This tubing will be used to make the individual channels for your manometer. Now you will have to go to the gardening section to find the next parts. You will need 2, 1/4" connecting T's, and 4, 1/4" coupling nipples. they look like these.



These are what will connect the tubing together. The T is for the individual channels and the coupler nipples are to go to the throttle bodies.

Now you need to assemble everything. Take the clear tubing and cut it into 4 equal lengths. They don't have to be exact but it helps the closer they are in length. Then you will want to cut about a 1/2" to 3/4 " inch off of one of the lengths of tubing. This short length will be used to connect the 2 T's together. Then you will connect a length of tubing to each of the other nipples left on the T connector. The 4 coupling nipples will go on each end of the 4 tubes that come from the T's. It should look something like this.



This isn't mine but is very similar in construction and shows in good detail how the manometer is put together. As you can see there are now 4 tubes that can hold a fluid and will self calibrate thanks to good old gravity. Yours will be smaller in scale to this one since it will be installed on a yardstick. Use ZIP TIES to fasten the tubes to the yardstick. You will want to keep them as straight as you can and you should run zip ties up to about the last 6" of the yard stick. You will want to drill a hole in the yard stick at the top to hang it from. Each run going up the yardstick will represent a paticular cylinder or throttle body on the bike. You will want to keep track of what tube is where. It is important that the tubes line up in the order that they will be attached to on the throttle bodies. 1-1, 2-2 etc. This guy here crossed his at the bottom. This is not a big deal as long as you know which tube goes where. In the picture above tube 3 is crossed over and is now actually connected to throttle body #2. Just line the tubes up in the proper order and you won't have issues. Also be sure that there are no kinks in the tubing at the bottom. The length is not important since they will self calibrate regardless. You will then need to fill the tubes with some sort of fluid. Water, new engine oil, used engine oil, anti freeze, anything can be used. Try to stick to products that won't hurt the engine. Things like MERCURY are not suggested. You will only need to have about 6" or so of fluid in the monometer to have enough range to work. The whole thing will look something like this. Again not mine but shows the simple construction.