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grizztracks · Posted: Sun Jan 22, 2012 8:46 pm Post subject: Carb Sync Tool

I made my own sync tool out of 12' of 5/16" vinyl tube filled with a little transmission fluid. I mounted the tube in a "U" shape on a 4' 1X4 pine board and filled it so I had around 22" of fluid in each side of the "U". You can only sync two carbs at a time but I've had good results with it. #3 carb (stator side) is preset so you sync 1 and 2 to it. There are only two screws to adjust (3 screws on 4 cylinder engines) which are located between 1-2 and 2-3. It's an easy adjustment that can make a big difference in performance.

Here are a few pictures of my Carb Sync Tool and it being used to sync the carbs on a Vector.
Note: never run the engine with only one side of the sync tool connected or you'll suck the oil out of the tube.

Carb sync (tool connected for #2 adjustment)

Carb #2 out of sync

Carb #1 slightly out of sync

Sync'd carb

TOMBOB · Posted: Fri Jan 27, 2012 11:45 am Post subject:

GRIZZTRACKS,
quesstions
1. is 12 ft of hose total or for one side or booth

2. at what speed do you test idle /wot

3.do you fill the tube up to 22" +/-

4. sync two carb's to 3rd at the all same height

5. 5/16 hose o.s.----?

thanks for all infor you give for this site

TOMBOB

TOMBOB · Posted: Fri Jan 27, 2012 3:06 pm Post subject:

GRIZZTRACKS,
43 degrees in michigan today so made your sync tool. less than twenty buck. booth 1&2 carb were out of sync. very simple idea but very effective.

thank again, very helpful

TOMBOB

aVenture · Expert Joined: 14 Mar 2005 Posts: 362 Location: Quebec

This differential type of guage always worked good for me, compared to the absolute type sold on the market. It is very sensitive, and contrary to a absolute connection, you can give it some gas after equalizing carbs so to have a feel how close the slides are opening together. All in all, this is not an absolute reading you need but the difference between cylinders, and it does it more precisely. The industrial one i bought for my bike has been collecting dust.

Oh.... i use antifreeze..

grizztracks · Posted: Wed Feb 01, 2012 4:45 pm Post subject:

4strokeluvr111 · Extreme Joined: 27 Aug 2011 Posts: 122 Location: NW Wisc.

IMO....anybody with a carb'd Vector (any carb'd Yamaha 4S???) that likes to tinker even a little bit on their sled should build one of these!

Easy to build and use. The hardest thing was getting the right amount of tranny fluid in! Head Bang

Thanks Grizz! Thumbs Up

Horizonls · Newbie Joined: 23 Feb 2012 Posts: 1

How would you proceed to syn an Rx-1 with 4 carbs, only two carbs have the vac lines attached to them and the other two are capped off?

grizztracks · Posted: Thu Feb 23, 2012 9:43 pm Post subject:

If a carb has a vacuum line for the fuel pump pull it and reconnect it to the tee in the sync tool line. If their is no vacuum line then pull the cap off, connect the sync tool and then use the cap to plug the tee in the sync tool line.

theewarrior · Posted: Fri Jan 11, 2013 9:14 pm Post subject:

All I can say is this works ....thank you!!!

gosnek · Posted: Sat Jan 12, 2013 7:44 pm Post subject:

Made one of these today,did a super clean on carbs was still having some issue, warmed up sled and hooked it up carbs where out of sync man what a difference after the sync. This site rocks

grizztracks · Posted: Sun Jan 13, 2013 7:17 pm Post subject:

Glad I could help Thumbs Up

Bradford · Expert Joined: 07 Jan 2007 Posts: 325 Location: NB Canada

I built one of these too. The only differnece is I used 2-smoke oil instead of transmission fluid. Finally found a use for that oil!