I got this idea from imortlfool in the Valve Synch Thread. But, since there weren't any pictures, I decided to post my own.
Basically, a manometer measures pressure (Mano- is the Greek term for "gas" or "vapor"). Many expensive manometers (like the Motion Pro or Carbtune) allow you to measure the vacuum of each cylinder in cmHg (centimeter of mercury). Since the starter valves on the VFR VTEC are supposed to be set equal to each other, then there's no need to measure the vacuum of each cylinder. All we need to know is what the vacuum in the cylinders are, relative to the other cylinders. Or, to be more specifically, what the vacuum of each cylinder is compared to cylinder #4. This is what the homemade manometer was designed to do.
Each of the four plastic tubes are connect to the vacuum lines from each cylinder. Each cylinder will exert a force on the oil in each tube. Essentially, the cylinders are playing a game of tug-o-war. Whichever cylinder is creating the most pressure will "win" and pull the oil in it's tube higher than the other cylinders. Our goal is to balance the starter valves so each cylinder is exerting the same amount of force, and therefore getting the oil level in each tube to be the same.
I used 1/4" inner diameter, 3/8" outer diameter plastic tubing to build my manometer. Each tube is 7 feet long. The reason I made the tubes so long was if there was a leak anywhere in the manometer or with any connections, oil can get sucked up into your cylinders (not good). With long tubes, you should have ample to recognized the problem, panic, and then hit the kill switch.
You'll also need two T-connectors and a small section of tube. This allows you to hook up all four tubes together. The best way to fill the manometer is from the bottom. With two of the tubes disconnected from the T-connectors, fill the tubes with oil (or another liquid of your choice, i.e. water). Connect to tubes to the T-connectors and turn the manometer upright. Gravity takes over and balances the oil levels in each tube.
If I remember correctly, the vacuum tubes on the VFR are 5/32" (3.5mm). So, I used some 1/4" to 5/32" adapters to connect the tubes togethers. Also, it might also be a good idea to got four 5/32" to 5/32" adaptors and some extra tubing (5/32" size). Disconnecting the vacuum tubes from the 5-way connector from in between the throttle bodies is not fun. So, to prepare for the day that I have to synch the starter valves again, I used the straight 5/32" adaptors and extra tubing to make the the vacuums lines on the bike longer. This will make it much easier in the future to hook up the manometer since the you can now pull the 5-way connector out from underneath the throttle bodies and disconnect it in the open.
Hope you you guys find this post helpful. Good luck synching those valves.
Edited by Darth Bling, 17 March 2008 - 01:12 PM.