Having replaced the O-rings on the fuel tees and solved my fuel leak problem, I've got the bike back together. I attempted to sync the carbs this morning - using a 2 port simple fluid manometer, filled with ATF. - Yeah, I know there are better tools for this, but this is what I have on hand.

Cylinders 1 & 2 went well - manged to get them within at most about 1/4" apart. When I try to sync 3 or 4 to #2, the fluid is rapidly pulled up the tubes towards the #2 carb. Only answer I can come up with is some sort of a leak in the tubing - but it works fine on 1 & 2.

Any ideas on what I am missing?

 

I would think that #3 & 4 need to be closed down some.
also, I think that you need to get them down to 1/8 inch or better.
I have found it best to look at all 4 at the same time because any adjustment on any of the 3 would effect the others.

 

I agree that all 4 at once would be better - but all I have to work with at this time is a 2 port manometer, so it each carb against #2. And I fully intend to try to get them closer - this was 1st pass at 1 & 2. When I move the connection to #3 or #4, the ATF gets sucked up to the #2 carb - indicating to me that it is "pulling" significantly more than 3 or 4. Trying to adjust the screw didn't get me any response before the ATF got to the top of the tube.

I did "eyeball sync" the rack before I put it on the bike - obviously not as close as I would have liked. So, does this mean I need to "close" 3 & 4 by turning the adjusters counter-clockwise a couple of turns to get them to a starting point?

 

Yeah, counter clockwise to reduce the vacuum.

I don't know if you had a look at how the carb mechanism works, but the adjuster screws run through a bar which is operated by the throttle cables, the screws are a fine adjustment for each individual carb.

 

In addition, the vacuum is checked between the carb butterfly and the intake valve.
By closing down the butterfly, you create more vacuum on the gauge.
so....If #2 has lower pressure (as you're stating) than say #3, you need to close #3 down to reduce pressure to balance the two.

 

When I did mine using a homemade ATF Manometer I had the same issue you are having. I had a 4 port meter but 2 of the carbs would overwhelm the others pulling the fluid almost to the carbs before I could make adjustments. I borrowed a single port vacuum gauge and set them individually prior to using the homemade gauge. It helped slow down the reaction a bit because they were closer to sync.

 

Bench syncing them will go a long way to having them close to being right once they are on the bike.

 

Based on results so far, I think I'm going to try a single gauge to get the #3 & 4 carbs to something closer. Apparently, despite my attempt at a bench sync, they are quite a bit out. If I can get them to something reasonable, I'll try the adjust to carb #2 routine again.

 

Did you use something like a feelers gauge or nail or needle or something like that when you bench sync'd

 

For the bench sync, I used a piece of wire from a loaf of bread tie, with the plastic burned off. I did have an issue with #3 - it didn't seem to want to close as far as the others although it would do so if "pushed." But, I'm thinking that if it were slightly more open, the vacuum would be lower, and that might account for the tendency for #2 to pull the fluid.