Old school sync

[Crackerborn]

I just thought I would share the high tech vacuum gauges that I use to sync the carbs after I finish breaking things. 

Old shade tree tools that worked on all the old 4 in-lines that had multiple carbs. I use 30 weight oil so if any gets sucked into the vacuum port it looks like an old 2 stroke marine engine. Pinch off all but #3 and whatever carb you are adjusting, then remove all the clamps and fine tune to a equal level. The Big Girl is now very happy.

[Momz]

Nice set-up

[JetDriver]

Crackerborn- want to take a close up pic of the board, and maybe size hoses or anything else pertinent.  Thanks.  Looks easy enough even for me.  Are gauges any more accurate?

[Crackerborn]

Here is a link to a similar setup http://www.vfrdiscussion.com/forum/index.php/topic/16200-homemade-manometer/ to the one I made, I just added 2 more lines. A well made manometer is as accurate as the best vacuum gauges available and it is a very old concept. Put water in intestines and you level pyramids, this just takes it to the next stage. I used 3/8" clear tubing because that was what the local big box hardware store had enough of. I would have preferred 1/2" so it would not be so hyper-sensitive to the vacuum fluctuations (bounce that you get on cheaper gauges). Getting the oil in the lines may be the hardest part of the assembly. If I were to make another one, I would make the board taller because if the Girls carbs are really off, the stronger vacuum can suck oil in a hurry and you need to shut it down quickly with the pictured rig. Just do a search for manometer and you will find all sorts of setups and choose the one the you think will work best for you. Total cost on the pictured setup was less than $25 (all tubing and fittings since the wood was laying around from some other project) and cheap and easy is in my wheelhouse.

[pancho]

I use a similar setup I made last year to do my carbs. I use ATF, and a reservoir made from black 2" plastic pipe with a six hole stopper in one end. The whole rig is about 5 foot tall.  

One thing to keep in mind is that for the fluid to rise at all, something must be able to partially collapse in response to the vacuum as oil will not compress or expand under pressure or vacuum, (in my case the reservoir, in crackerborns the tubing itself) and no air in the fluid part of the system as air can be rarefied and allow the fluid to rise too high  (into the carbs).

 I used very thin tubing,, maybe 3/16 and the ATF will rise maybe 24 inches under vacuum....   remember, the more the fluid rises from the resting state, to the testing state, the more sensitive the setup. (If your fluid only rises one inch when testing, you don;t have much visual to go on to adjust) I am away from home so I don't have pictures available.

[JetDriver]

Good stuff.  I may finally try making one of these!   If I'm understanding correctly, smaller diameter tubing shows the variations to a greater degree, larger diameter is much less volatile and easier to read?

[97Valk_CT_Euless]

Nicely built.  I made a similar design a year or so ago, but not nearly as craftsmanlike.
I like the 1/2" tubing idea.  Mine's 1/4" and things can sure happen fast!

Disagree a bit with Pancho's operation description, at least of this style.  I have no idea how yours is built Pancho so I'm not saying your wrong about your design.  This one is a differential manometer.  The height of the levels will measure the difference in pressures between them.  No compression or collapse is required.  The fluid flows between the tubes.  That's why it will rise and flow all the way into the engine.

Not sure why you have to pinch off the cylinders your not adjusting.  They'll all read at the same time.  Kinda fun to watch.

Diameter won't affect the height change, but it will affect the speed.

[pancho]

My design is different than what is shown, with a common reservoir that will respond to the outside air pressure. The fluid in all six tubes will rise approximately 24" (if the carbs are close to being synced) from the resting position (which is just above the reservoir) when the bike is started.  Very sensitive and easy to compare differences.

If the fluid/oil in all six of yours does not rise under vacuum, just rocking back and forth between tubes, then yes, you are not relying on the same principles as what I designed mine around.  However, since the one shown is made from flexible tubing, I would think that it will respond to the outside air pressure and collapse if only a bit when the engine vacuum is is applied..???

I may