I made a homemade sync tool for my V-star 650, but it was just for two carbs. So my next thought was that I will make a 4 carb set-up for my RSTD. But I started reading the directions in this forum and realized that the proceedure is for balancing Carb 1-2 and then 3-4 and the final proceedure was 2-3 (this is to sync right to left).
So I gave it a try with my homemade job and it improved the way the bike was running (much smoother than the bike has ever been). I bought this bike about 2,500 miles ago and thought it was always just a little off.
It did take longer (extra 10 mins max) to move the hoses, but it seems to work.
It was really out of balance left to right. I'm glad I did not wait till I could get the extra time or money to get a 4 carb balancer.
It sure would be nice to have all 4 of them hooked up at once and I will likely make one.
But I guess the point is that if somone is one a tight budget or has access to a 2 carb tool then go for it.
It is important to note that the carbs that are not being measured need to be hooked back up .
When i went to 3-4 I forgot to hook up the vacuum line and plug on carbs 1-2. I wondered why it was idling so poorly. It was a lot easier once I hooked them back up.