$5 Carb sync tool

Materials:

20 feet 1/4 inch clear tube
6 inches 1/4 inch vacuum tube
1 inch thin hollow tube that will fit inside the 1/4 inch tube
100 ml 2 stroke oil
Roll insulation tape
Broom stick
$5
***picture $5

Method:

Find the middle of the length of tube and form it to a U bend, you do not want to kink the tube.

Attach tube to broom stick with the tape with the U at the bottom.
***p bend
Fill tube with 2 stroke oil so that the oil fills to 3 feet from the bottom of each side of the tube. Fill slowly to avoid bubbles. Let any air bubbles work their way out. Oil on both sides should be at the same level when air is gone. 2 stroke oil is used so it will not damage the XJ motor if it gets sucked into the running motor (could happen if sync is REALLY off).

Cut the 6 inch tube in half making 2 x 3 inch tubes. Cut the thinner 1 inch tube in half making 2 x half inch tubes.
***p small bits of tube
Push the half inch pieces inside the 1/4 inch clear tube and then into the 1/4 inch vacuum tube.
***p closeup
The small tube acts as a buffer making the oil "pulse" less with the motor running. The vacuum tube is used as it is less likely to melt if it contacts the motor while it is hot.

***P Completed Sync tool

Use:

Take the XJ for a ride to warm it up.
Get home and place the bike on centre stand. Working quickly, remove the tank and attach temporary fuel supply.

Insert YCIS tool.
***Picture of bit to inset YCIS tool into 8O
Note you don't need to do this step. There is some debate about the use of the YCIS tool. The YCIS passage links the 4 cylinders together. Some claim that Yamaha says it must be used and that this way ensures that each cylinder is not effecting the others. Others state that they think as you do not ride with a YCIS tool inserted (oowwww) that it is better not to use it. Some who have tried with and without using the YCIS tool say it makes a difference. Try it both ways, report what you find. I will when I get round to making a YCIS tool to see for myself.

***P YCIS tool
***Link Home made YCIS tool instructions

Aim a fan at the engine (I use a car fan mounted to a battery, fan can be got from a breakers yard).
Connect tubes to cylinder 3 and 4.
***P 3 connected
Start bike.
***P 4 start button
Adjust sync screw so oil becomes level.
***P level
Note that even the pressure of the screw driver on the adjustment screw can affect the reading, a gentle touch and good fitting screw driver is required.
***p screw driver seated
If you have had the carbs off the bike you should make sure the adjustment screws are clean and turn them a few times each way to "exercise" the threads.
Bench sync to get them as close as you can.
***p sync guages
If they are not to be removed from the bike, note the positions of the sync adjustment screws then turn each one in a couple of turns then out 4 turns then back in to your starting point. This exercise makes adjustment a lot easier.
Turn screw slightly and watch result (the oil should climb slightly in one tube and fall in the other.
Don't make large adjustments.
As you adjust the screw you will see that eventually even the slightest adjustment will get the oil level moving. A small blip of the throttle every now and then will make sure the adjustment screw is seating properly.
When the smallest of adjustments makes the oil level change direction, this means you are very close.
Small adjustments will now get it spot on level.
Turn bike off. Let it cool a while, be careful that the bike does not get too hot. If smoke is rising from the rear of the engine it is too hot!
***p smoke
Repeat for 1 and 2 then 2 and 3.

There are other ways and tools (some very expensive) to do this job.
***l2 carbtune morgan
This method and tube has worked for me.
***p pick of me (maybe)
I have found it to be rather easy and very accurate.

Pictures will follow in a few days when I re sync my bike.
Pictures of the Tool should follow tomorrow if I get the time.

 

Yes I want to see pictures!
Does this really work?

 

What's with all the astericks? Are these banned words and links?

Jim

 

Yes - please show pics!!!

 

Astricks waiting for pictures!

Sorry been moving and really busy, 20 years worth of junk to sort out!
Oh and I am on broadband now so won't take all day to upload. Today maybe!



Yes it really works!

 

how are those pictures coming along?

 

To make the fluid pulsate even less ...
Search:

Restrictor
RickCoMatic

Making those restrictors will calm thing down ... a lot!

 

the "KiwiXJ750D" invention/apparatus sounds good. I've got a pile of clear hose from hospital--oxygen masks. What would happen if you ran all 4 hoses from the intakes, thru the restrictor-filters, down the broomstick, and into a 4-way vac TEE? Same set-up but now it should work almost just like expensive carb sticks! You could tweak all 4 at the same TIME!

 

I imagine it would make things more difficult. Instead of having just two carbs affecting the oil level, you'd have all four affecting it and throwing off your readings a bit. It would be possible, but why make such a simple routine (synch 3/4, synch 1/2, synch 2/3) more complex (synch 3/4, synch 1/2, re-synch 3/4 because 2 was pulling more oil the first time, re-synch 1/2 because now 3/4 are closer and you see that 1/2 needs more work which throws off 3/4 again, ...)

 

I can't see doing all that plumbing. Short of having a set of Vacuum Gauges that are made for the job ... (Stainless Weights or Mercury) ... why not just do it Old School and just use one accurate Vacuum Gauge with a Restriction Device to calm-down the Vacuum impulses.

You'll get just as accurate a setting as you would with all that tubing and such.
It just takes 15-20 Minutes longer having to swap the Gauge over to another Vacuum Nipple and close-off a Vacuum Line with a Golf Tee.

The end result is still having the whole rack in Sync!

 

Where did the pictures go?

 

This is the tool I have used...

http://faq.ninja250.org/wiki/How_do_I_s ... tle_method

2 bottles... works pretty well.

 

This is what the original poster described:
http://www.obairlann.net/reaper/motorcy ... meter.html

 

Woot,
That's the same thing I use. I do not have any type of restrictor inline. I have automatic transmission fluid in mine (pretty red!) so I am able to see it well. It does move around alot when the engine idles, but is acurate as can be. I originally made it for my V-twin (Honda Shadow) but I found I can also use it on my 750 Seca too. I synch the left two cylinders to each other (#1 & #2) then synch the right cylinders to each other (#3 & #4) then synch the right two with the left two. Sometimes I need to re-adjust the idle speed when done.
I mounted mine right on the wall in the shop so It's ready whenever I need it. Apart from removing the tank and mounting my temporary gas supply up to the bike, it takes about 15 minutes to synch the carbs properly.
The reason for using the restrictors inline on the homemade synch gauge, is the fact that some have sucked the fluid over the crest of the clear line and into the carbs (not a good idea) I just shut the engine down and adjust the carbs to prevent the fluid from being sucked into the carbs. PD

 

I made a two cylinder balancing deal. How should I pair the carbs up. 1/3 then 2/4 then balance the pairs?

 

I made a two cylinder balancing deal. How should I pair the carbs up. 1/3 then 2/4 then balance the pairs?

 

1-2, 3-4 then (1-2) - (3-4)

 

Why is it that way? Are 2/3 and 1/4 paired up? I'm just trying to understand my machine better.

 

3 is the "Master" and is controlled by the idle screw.
1 leans on 2 which leans on 3. 4 also leans on 3 from the other side.

Adjusting 2 automatically adjusts 1 the same amount, so they need to be the same from the beginning.

a link to a more comprehensive sync thread

 

No.

#3 is "home base." It has no adjusting screw other than the main knob that adjusts the whole rack.

#1 is adjustable but tied to #2; whatever you do to #2 it brings #1 with it.

#4 is adjustable.

So you sync #1 to #2; then adjust #2 (bringing #1 along) to match #3. If you're using a 2-bottle rig it might pay to compare #1 to #3 at this point; but remember if you adjust #1 when comparing to #3 you need to revisit the 1-2 comparison again.

#4 just gets synced to #3.

The big knob is how you adjust the idle to 1050rpm (1200 for the 550s) once the YICS is unblocked.