I built myself a nice manometer to sync my carbs. I used two stroke oil and learned quickly that number 4 was rich LOL.
After waiting for the oil to settle in the meter I started it again only to end up in the same place, more oil sucked up by #4 LOL.

I went on Amazon and purchased myself a set of Vacuum Gauges.

They arrived today.

It took me a bit to get the gauges hooked up. First thing I did was remove the left side upper motor mount then I removed the plug from #1 with an 8mm socket then pulled the 3 vacuum caps off cylinders 2,3 and 4. I then hooked the 4 rubber vacuum lines up to each cylinder and then to each respective vacuum gauge 1 through 4 (left to right). Each gauge is fitted with an adjustable valve. I closed these valves prior to starting as I hooked them up with the engine cold. Starting the engine with the choke closed could damage the gauges. I turned the key, closed the choke and hit start.

After my engine warmed for a bit I set idle at 1400 then reached down and opened gauge 1 a 1/2 a turn then gauge 2 then 3 then 4. Then 1 again another 1/2 a turn then 2 then 3 then 4. Then back to 1 then 2 then 3 then 4. After the last 1/2 turn the needles on all 4 gauges were bouncing pretty good. Starting at 1 I turned the valve slightly clockwise (close) until the needle settled, then 2 then 3 and then 4.

This first pic shows my setup hooked up and ready to start.

 

This next picture shows the gauges with engine running. As shown none of the cylinders are even close to 3.

 

SO, I did not have to remove the air box from the bike. I did not have to remove the gas tank from the bike. I did however have to loosen the front bolt on the tank, remove the seat and remove the rear bolt and spacer from the tank. I had to prop the rear of the tank up 5 inches to get the screwdriver on the adjustment screws to sync.

After some tweeking, I managed to get 1&2 close and 3&4 close.

 

This is when things got a little interesting........

 

I placed my screwdriver on the adjusting screw between 2 and 3. As I started turning the screw the idle went lower and lower. The vacuum gauge needle starting to come in to sync with 3 then the bike just died. I thought oh no, must be low on fuel with the angle of the tank. After checking, all was fine. I closed choke and hit start. She fired right up with a gentle twist of the throttle and I continued. After a few minutes the sync screw had no affect and then the engine died again. I started with choke again but this time I held the throttle open a bit and started turning the idle adjust screw. I must have turned it in 8 full turns. Then adjusted it back out to 1400 RPM. Bike sounds much better now with 2 almost synced I grabbed the screw for carb 1. After a few minutes and another idle adjust. I had good needles all really close in sync right through the revs up to about 6k (I felt no need to rev higher) Very happy!

 

Prior to syncing the carbs I had an erratic idle, low speed with clutch out was very jerky, taking off from full stops was a bit of a pain if I didn't get the revs up. All of my issues were at low throttle up until 2k then it cleaned up. My revs were also hanging on throttle blips.

Different bike now LOL. Way smoother, pulls hard and smooth. Blips are precise and take off from full stop, sounds like a pro!

 

Great write up. Also, your pics show why it's important to use a 4 gauge set instead of moving a single gauge and move it back here.

 

I agree that is it a nice write up. However, there is a slight flaw in your procedure. Prior to attaching the gauges to each separate carburetor, you need to calibrate them so that they all will read the same given the identical circumstances.

Here me out here to see what I'm talking about.

Now, this is the part that people don't want to hear. First and foremost, you need to ensure that the valve clearances are within tolerance. Valve opening has the greatest impact on the amount of air that is drawn into the engine, and the amount of vacuum that each cylinder is creating.

Then, you need to make sure that each of the gauges and the vacuum lines that attach them to the carburetors will read identical readings if attached to the same environment. The only way to do that is to attach each gauge, as an example, to carburetor #1 vacuum port. Make the adjustment to the inline hose valve until it achieves whatever you expect it to read. In this case you want it to be a steady reading. Once you have that one adjusted, disconnect it and then connect the second gauge to carburetor #1 and adjust it so that it has the same reading as the first, including the identical value. Proceed with the rest of the gauges.

Once you've done this, then you can connect the gauges up to each of the separate carburetors and do the synchronization. Only this way can you be sure that the readings you're seeing on the gauges truly reflect what's happening.

Now, all that being said, it seems that you've achieved some good results. If you want to check your gauges, you can do the calibration procedure now and see if when you connect each separate gauge to the vacuum port on carb #1 that you're getting identical readings. If the readings are the same, then all is good. If they're different, then maybe you could have even done better.

Anyway, my

 

Just curious, what do you hook the number 1 to? I can see 2,3,and 4 have a lil nipple cap on them! Just always wanted to know.

 

I'm assuming that each cylinder has its own vacuum port, so each gauge is hooked up to a vacuum port.

SteveandMat, I see you didn't have much luck with the DIY manometer. I'm actually in the process of building one right now. My 5mm adapters are in the mailman's bag as I type this. heheh
I'm going to make 15 inch traps with 1" PVC pipe so that nothing gets sucked into my engine.
Maybe it is just better to buy the gauges...too bad you can't just rent them some place...that may not be a bad idea to rent these out.

EDIT:

I was trying to confirm the procedure on how to set the pilot fuel adjustments and syncing the carbs.
Obviously, syncing is the last thing you do or to some level, I'll tune both at the same time.
I'll figure it out when I'm in there.