View Full Version : Synchronization of carbs

Oct 5th, 2008, 11:52 AM
Help ! I'm trying to calibrate a sync pro tool and when I connect it to vacume it trys to suck the fluid out of it . What am I doing wrong ?

Oct 5th, 2008, 12:48 PM
i sent pvt message

Oct 5th, 2008, 06:53 PM
way too much vacuum. it will do the same thing if you twist the throttle when the synch tool is connected. You can only pull as much vacuum on that tool as you have at idle rpm

Oct 5th, 2008, 07:07 PM
Thanks, I'll try more fluid. Back to the shop !:)

Oct 5th, 2008, 07:14 PM
just to reiterate - get the bike started and warmed up so it will idle at normal idle speed without any choke. You dont want a high idle. THen when the synch tool is hooked up ONLY let it idle - never twist the throttle

Oct 5th, 2008, 08:40 PM
madkaw is correct.
low idle and warm to set sync.

in this case..
his sync tool was bubbling.
I found on mine the fluid evaporates so.
barney added liguid and it solved the bubble prob.

Oct 6th, 2008, 08:05 AM
Idling at 900 rpm and still pulling the liquid up and out . Hey guys this honda really sucks ! (runs really good though)

Oct 6th, 2008, 05:21 PM
what unit is it? mine has mercury in it

Oct 6th, 2008, 05:51 PM
Idling at 900 rpm and still pulling the liquid up and out . Hey guys this honda really sucks ! (runs really good though)

the honda is great.
the tool sucks.
barneys was made cheeply also.
we have 1 adj screw we have to have almost all the way out..
just to make the guage read even..

jan, he has the white one with blue fluid.(plastic)

I'll get barneys guage to try if you like.

Oct 7th, 2008, 08:27 AM
Thanks guys, the tool is a "motion pro" sync pro......1 yr old.. Starting with the engine hot, idling @ 900 rpm +_50 never touched the throttle. Could the o-rings on the screws be pulling air past them ? Its always been stored in a box so my friends won't see it and borrow and not bring it back :D Thanks for the offer of the gauges . A friend has a set of JC WHITNEY gauges I might go get. But I'd just be tickeled to get my $100 gauge working

Oct 8th, 2008, 09:17 PM
wait , what are you trying to do? are you adjusting idle air screws or are you synchronizing the carbs?

those idle air screws should only be about 1 1/2 turns out.

Oct 9th, 2008, 08:21 AM
Oh sorry , the screws that I speak of are at the bottom of the high tech professional vacume gauge that I am fumbling with . At the bottom of the glass tube is a small reservior with an adjusting screw to calibrate the 4 tubes for an even starting point . You're supposed to calibrate the tool b-4 you start. The gauge is a closed system.... the vacume pulls against the reservior .

Old School
Oct 23rd, 2008, 01:24 AM
what unit is it? mine has mercury in it