carb sync results

O.k. so I sync'ed my carbs on Saturday, and here's what I came up with. I started with yics tool in bike, and balanced them like that. Fairly easy to do. Then I pulled the tool out, put bolt back in hole, and started it up. My middle 2 carbs were getting more vacuum than the outer 2, in fact it was enough to empty the fluid out of the outer 2 hoses and fill middle 2 to top. So, I sync'ed them with tool out. Also fairly easy, just every time I would shut bike off, and restart, they would come out a little different. So then I put tool back in to see if outer 2 carbs were pulling more than inner 2, and for sure they were. So I just left it as it was without the tool. I will have to look around a little and find link to the yics tool I built, because I found 2 prints for it, and they had 1 minor difference, but i can't remember off the top of my head what it was.

 

Excellent observations. This should be useful. I hope more folks chime in with their experiences so we can see a trend in behavior.

 

Here is the link to the yics tool I built: YICS tool I built

And here is the other tool: Other drawing I found

The difference is the one I built has a 5/8" piece of tubing after the 3/4" washer, and the one I didn't build has 7/16 piece of tubing. Also, one of them has 4-1/2" tubes between rubbers, and one that I built has 4-1/4". I wonder if this makes a difference?

 

sounds like a homemade gauge
they will be way more sensitive than a mercury or steel slug gauge
sometimes it helps to work the screw in and out a bit, like 1/4 turn each way
just to let it turn smoother
don't expect perfection a water gauge is to sensitive, depending on the type, the weight of the screwdriver can change it, a oil gauge is even more sensitive

 

I also did forget to add that it is homemade, with Marvel Mystery Oil for a fluid, so it is pretty thin. But my problem is not with the results being different every time, because it was only a cm or 2 off it was the difference in using YICS tool to not using it.

 

The... ah, problem is one of ... how do you say in America ... "F-ing-up the Reverse Engineering.

Three expanding hose sections ... needed to isolate 4 Carbs.

The "On Center" measurements need to be PRECISE for the 3 sections of Rubber Hose.

Measured from the end of the Tool that's inserted far into the YICS Port.

The Last expanding hose section:
Function -- Actually Covers the #-3 orifice to the Passage.
3.0 cm from the very end of the tool-- On Center.

The "Middle" expanding hose section:
Function -- Actually Covers the #-2 orifice to the Passage.
16.5 cm from the very end of the tool-- On Center.

The "First" expanding hose section:
Function -- Closes-off the Opening of the Passage preventing air from entering the Passage.
29.5 cm from the very end of the tool-- On Center.

The Flat washer, just inside the Wing Nut, on the Plans for the D-I-Y, Home-made, Internet-job Tool:
Function -- Insertion STOP ~ Intended to accurately place the Hose sections for expansion when the wing nut is tightened.
32.0 cm from the end of the tool-- On Center.

 

Looking at my 550 with the carbs and tank off, it looks like it should be fairly easy to just measure where the ports are on the engine block or head to come up with the spacing. Is there any particular reason not to use longer hose pieces to make sure you've got each port covered correctly? After all, I've read where one guy on here just shoved a piece of hose in there the whole length of the YICS gallery and compressed it with the plugs to expand it. (?)

 

That works.

I stuffed the Passage with a long strip of Cotton T-shirt tied-together... soaked with Olive Oil because we didn't have any Marvel Mystery Oil and all the stores were closed.

 

Could'nt I just add another piece of rubber hose at the handle end, and put the other 3 between carbs 1-2, 2-3, and 3-4? The only reason I dont like the one long hose (lenght of passage) idea is, won't it expand more in the middle than on the ends causing 1-2 and 3-4 to be still together?

 

Success depends upon isolating the four Carbs.

That's why I kinda like the long strips of T-shirt Method.

Open BOTH ends of the YICS Tube.
Pull a real-long, square-knotted together, length of 1/2" wide T-shirt "rope" all the way through the Passage.

Lightly wet the portion pulled-through the Passage and have an assistant Pull it BACK until they have it where you wet it.

Working together ... from opposite sides ... wet and stuff the T-shirt IN until it gets packed-in at the middle.

Keep packing each side until the passage is tightly stuffed.
Trim enough off each end to allow the Bolts to be re-inserted.

Do the tuning.

When the tuning is done ...
Remove the Bolts.
Pull-out the stuffing.

Lastly ...
Soak some "Patches" with Carb Cleaner and Push them all the way through ... Cleaning-out the Passage of any product to wet the Cotton.

If the Passage is stuffed right ... there will be No vacuum effect because the Passage is completely blocked.