motion pro sync tool,

Jeff.Saunders wrote:

I do use carb sync tools, but I'm very careful about how much I adjust the carbs AFTER I've synced the carbs on the workbench.

If you are dealing with an old set of carbs, the sync at idle can be influenced by wear in the carb. Air can leak past slides and idle passageways may not flow fuel or air the same as when new due to corrosion or gasoline deposits.

With Z1 and fully mechanical carbs (not a CV carb). I sync the slide heights with a thin round piece of metal (actually a partially unwound paperclip). Then when I make an vacuum adjustments I only tweak any one adjuster a very small amount (1/4 turn or less).

I adjust the air screws/fuel screws to help sync the idle more than any slide linkage adjustment

While a super smooth idle is nice, it's more important to have the slides fully sync'd when the needle / needle jet come into play in the mid range.

Superb info here! +1

ALWAYS bench sync. Then if a reading is very low vacuum when dynamic syncing, and you have to lower the slide very far to achieve sync, there is deffinately an air leak present between the slide and engine.

When the slide is RAISED to sync/or add more fuel/air on a carb @idle, the vacuum DECREASES.
When a mixture screw is tweaked closer to the best power mixture @idle, the vacuum INCREASES.

GL all.

I bench sync mine as well, i use welding wire .025, so i guess i bought the sync tool for nothing ... WANT IT BACK ????

master carb ???so which one is that,??1.2.3 or 4 because i dont think that applies here

stonemaster wrote:

I bench sync mine as well, i use welding wire .025, so i guess i bought the sync tool for nothing ... WANT IT BACK ????

Bench sync, before vacuum syncing.

Dynamic vac sync is absolutely necessary.

In a perfect world where all cylinders and all carbs performed equally, the bench sync carb settings alone would be sufficient, without any need for a subsequent running sync.

But air/fuel requirements for best performance varies among the cylinders, even if ever so slightly. So the carbs are used to achieve matching best performances among the cylinders.

Intake vacuum measures a cylinder's performance.
Thus, achieving equal vacuums also achieves equally performing cylinders.

Imo, the running carb sync procedure might be more accurately referred to as syncing performance among the cylinders by adjusting the individual carbs.

Good Fortune!

this tool is a POS, Followed all instructions to the T, wouldn't even calibrate correctly, Lame, i can do better by ear, NEXT ....

If you are really unsatisfied with the Motion pro tool, maybe you can return it? If not it will sell easy enough on CL or Ebay. There is a lot of good advice there for after a bench sync not to get it to far off that point, as it should be a fine adjustment after the bench sync to balance the cylinders while running. I use a numbered wire gauge drill bit like a feeler gauge to set the butterflies or slides evenly.
Here is a thread I started 1 year ago, and there are a lot of good Ideas here for a home made set up. I still use the 1 I built for $6, although I have added some restrictors to each of the 2 hoses. These really work, and even the slightest movement of your adjuster will register with the ATF in your "Gauge".

i've used motion pro pro series carb sticks for years and about the only time you will run into a problem is if you leave them vented to the atmosphere to long the mercury can evaporate or draw in moisture when that happens you can buy refill mercury for them.

stonemaster wrote:

this tool is a POS, Followed all instructions to the T, wouldn't even calibrate correctly, Lame, i can do better by ear, NEXT ....

Many people have been successful with this tool.

If it wont calibrate correctly, there is deffinately a setup issue as it can be done off the bike. Just hook the four lines into the 5-way tee and suck on the last opening watching the liquid rise up till about 1/2 way. Plug the hole with your tongue and then calibrate the levels with the screws around 1/3 height of the instrument. Works great!

I used to do the ear thing until I got a Morgan Carbtune Pro, then I realized how bad my ears sucked. :laugh:

GL.

they dont use mercury that the problerm I see, it would function much better with mercury than the propelyne glycol crap, oh well cant win em all,

i use the new motion pro's. i find them to be accurate but the carbs are the finicky part.

in order to get each slide the same i have to keep stabbing at the setting’s. I have rs34 carbs. dif carbs will have dif adjustment techniques. the rs carbs really need a FINER fine tuning setup. it is a bit of a pain and a guessing game to tune them. i just keep loosening the top screw, turning the adjuster (the smallest amount imaginable) then retighten the lock screw. u just keep over shooting , then repeating until u finally get it right.
The process is a pain but it it is not the fault of the gauges; they seem to be very accurate.
on some racks of carbs, 1 carbs slide is not adjustable. this is the master carb. all other carbs are set up to mimick the vacuum reading of this carb.

not being one to give up easily i will be giving it another go. I havent lost fluid, I set the unit up correct as per instructions, upon attempt to calibrate the first two shot fluid all the way to the top and would not come down no matter which way I turned the adjuster screw. this was on the bike, I will try again later off the bike, thanx for your responses and if you have anymore tricks lemme hear em, sorry bout sounding pissed but that wasnt my only problem last nite, got a new timing gun that is overly sensitive to heat, it has issues hahaha