Problem Syncing Throttle Bodies

[tarock]

Hey all! This is my first post even though I have loved the information deemed from the cite since I bought my busa two months ago. I was hoping I could get it figured out, but my do-it-yourself TB synco has me at a loss. I bought a mercury manometer and had the bike basically synced when I decided to try and fine tune it a little more. I somehow in the mess got 1 and 2 way off. Now, 1 is running way high (high on the stick, I don’t know if that means rich or not) and for the life of me I cannot get 1 back down to the others. This problem leads to constant influxes in idle speed when I adjust 1 and 2. It also has the tendency to kill the bike because the others are so low and so they die out (2,3,4).

Before I hurt something, is there a base/stock/reset setting that the adjustment screws should be at...or am I just SOL and just have to keep on doing the trial and error technique?
Thanks in advance for the help!

 

[Fastfoshow]

Jinkster's "how to synch your busa"

 

[mike1180]

Welcome!



I don't think there is a default setting, you will just have to try to finish it.
Adjust the screw between 1 and 2 (left side) and then the screw between 3 and 4 (right side), and then the middle screw for the 2 pairs together, and it should work.
Does that make sense?

 

[tarock]

Thanks, and yes I was using Jinkster's guide (which is great) until I really got myself in a pickle.

I will try and get my 1 and 2 back together...I guess my problem is 1 is so far off from the others haha.

 

[MC MUSTANG]

Tarock, start the bike and make an adjustment to #1 and 2 to see what effect it has. Meaning turning the screw ccw raises or drops #1... once you are comfortable that you know which which direction drops #1, then shut the bike off and give it at least a turn in that direction and then start the bike again. Recommend that you have someone monitoring the idle while you are doing this for two reasons: one to ensure that you idle stays above 1100 so that the bike will run and two so that the bike doesn't rev above about 5.5k (don't want to suck mercury into the motor...) see if that helps. Centering the screws may be a last resort but may not "reset" to any center value.

I hope that helps?
MCM

Based on where you see the others - if you think you can gauge where 3 and 4 are in relation to 1 and 2, after you make adjustments to 1 and 2 you can try and bring 3 and 4 up, then start the bike and see where you sit...

 

[tarock]

So i will be the first to admit that not counting the turns to seat on the adjustment screws prior to starting this project was STUPID! Now that I have that said, I am way off on my sync. Cylinder 1 is way high and everything else is barely registering. I also have no idea where to start with my adjustment screws...I have tried seating them all and bringing back up and starting with them all the way out and working them in. No matter what i do my 1 is always way off and i dont know where to start. I am really worried i will be hurting something due to my other banks running so low on the level.

 

[mike1180]

When you sync the throttle bodies, you are adjusting the butterfly valve linkage so each throttle body passes the same amount of air (and fuel) as the rest.
This is done by measuring – equalizing the vacuum produced in each intake duct.
If they are out of synchronization, it can result in increased fuel consumption, increased engine temperature, poor throttle response, and higher vibration levels.
I would really try and fix it, you really can’t leave it like that.
One different described way that you may try (I have not) because you have 1 cyl way out is this:
Let us know how it works!

You should start with the TB that has the idle adjustment. I call that number 1, then count right to left, right being if you were sitting on the bike. It's really simple, least it has been for me.
1. Set the base idle to 1500. That smoothes out the idle some, spec idle is too rough for a good vacuum reading. Check reading on 1.
2. Using the screw between 1 and 2 match number 2 with number 1. Readjust idle speed cause it probably changed, and double check 1 and 2, tweak as necessary. Blip throttle, but not much you'll risk sucking in the liquid. Blipping the throttle after each change settles it in, that's why it changes after it gets put together, a lot of folks don't do that. Check idle speed.
3. Match 3 to 2 the same way. Blip throttle, tweak idle again, then double check it with 1 and 2. Tweak as necessary, check idle speed.
4. Match 4 to 3. Blip throttle, tweak idle again, and double check them. They should all now be within 1" of each other.
Consistent smooth idle speed is the key, blipping moves things to just like they are when you ride, it settles things in and does make a difference. Set idle to spec, and ride it!
Reason I work right to left is say you turn the screw for number two. You also open three and four. You turn the screw for three, you also change four. That's why I don't subscribe to set 2-1, then 4-3, then 3-2. They're not Siamese twins, they're separate units.

https://www.hayabusa.org/forum/main...anybody-who-has-used-motionpro-syncpro-2.html

 

[tarock]

So after a full day of trial and error i got the bike back in tune. Thanks for all the the help guys!

 

[mike1180]

That's how it's done.
I guarantee it will be easier the next time.
Always is.