carb sync sucks

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dij0674

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Hey all
im trying to sync my carbs with the motion pro sync tool and the fluid keeps getting sucked into the engine during the calibration step... Any ideas how i can stop this.
DID
 
Hey all
im trying to sync my carbs with the motion pro sync tool and the fluid keeps getting sucked into the engine during the calibration step... Any ideas how i can stop this.
DID

I don't have the motion pro but mine have an insert you put in the hoses to prevent this. Do you have all the parts installed on yours?
 
I think i do restricts installed on the carbs side of the hoses. Connect to #2carb and al the fluid goes up the tubes into the vacuum tubes.
 
I think i do restricts installed on the carbs side of the hoses. Connect to #2carb and al the fluid goes up the tubes into the vacuum tubes.

do you ahve it connected to all synch ports?
 
maybe a pic of your set up to help us diagnose but ya rhoy idea is a good one, will get you real close to perfect, use a drill bit or your eye works good, if you have good eyes hehe, hold up to the light and match it up, works great
 
My set up is stock carbs and a motion pro tool. Im supposed to hook it to the port on carb 2 and calibrated it. Then hook each tube to a port on ea. Carbs but i can't get past the calibration step. When i connect the single tube to the vac port and connect the four tubes to the spliter they supplied. The vacuum pulls the fluid right out of the tool.
 
never used the motion pro just the carb tune + weber, so you cant just hook all four and go from there? anyways try the visual sync, will get you pretty close to perfect, if your that far off not sure.
 
for the 70 bux i spent at princess auto i got all 4 vaccuum gauges , the mig tips and the tubing,ide toss that midevil carb sync and trade up for this setup imo
 
mmm maybe try hooking to carb one only for fun and see how it reacts or just hook all four up, does it still try to pull it thru the roof?
 
if you only have vaccuum on one port, i could see it pulling fluid through! i know my carbtune (mercury) would. i'd hook all 4 up.
 
You have to hook all four lines up to the #2 port at one time to calibrate, if just hooking one at a time thye fluid will be sucked out.
 
How fast do you have the idle set for this test? Shouldn't be over 1150-1200 rpms, at MOST. Revving the engine more than a slight blip
with one of the merc type sync tools is always a no no.
 
I have the same tool and have had no issues with it....very strange? Maybe the restrictors are too big?
 
There are calibration screws that should be set as far counter clockwise as they will go. Not too hard though as they are backed out against plastic stops. this will put the fluid to a point as low as it gets. They should have been set this way by the factory. Once you have all connected to the #2 cylinder, they are adjusted for initial range at about 1,000 RPM and should be about 1/3 up the tubes and equal between all cylinders. You adjust this yourself with the screws of the Carb Tune. If you are going to adjust the carbs at that idle point you then hook individual hoses to all 4 vacuum ports and adjust the carbs so that all tube readings are the same again. All Done, You are sync'd...

Good Luck,
Dave

PS: It's a pain to set up but I'm using Marvel Mystery Oil instead of their proprietary fluid...
 
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