Airscrew Adjustment to fix off-idle stumble and Throttle Body Sync - w/ pigtails

Joined
Mar 22, 2016
Messages
15
Location
Malaysia
Hai any explain...why your right pilot air screw 3/4 turns
And left side is just a litle from right..and why both side not equally turn...I am looking that is same cylinder same Cc..why there are different pilot screw adjustment.. Same fuel injector...with same air coming... Thank..can share ideas
 

Checkswrecks

Ungenear to broked stuff
Staff member
Global Moderator
2011 Site Supporter
Joined
Mar 7, 2011
Messages
10,200
Location
Damascus, MD
Yamaha world crosser said:
Hai any explain...why your right pilot air screw 3/4 turns
And left side is just a litle from right..and why both side not equally turn...I am looking that is same cylinder same Cc..why there are different pilot screw adjustment.. Same fuel injector...with same air coming... Thank..can share ideas

Because the total movement of air through the length of each side is different. It's not just about the cylinder, there are differences in how the air gets to each cylinder, and differences in the two sides of the exhaust system. The cylinder is just a middle portion of the entire route.
 

JV

Member
Joined
Dec 11, 2010
Messages
64
Location
NE Arkansas
From a post on the 1st page I used the all things being equal method and backed out both adjustment screws 3/4 of a turn.

That took care of the low speed/idle surging that has seemed to appear here recently.

I do have a home made U tube manometer but I couldn't find anything to pass for a tee for the left side.

I thought I'd check it later but for now it made a great deal of difference.

Idles along fine at 8mph and the surging is gone. ::001::

The right side with the white paint was closed and the left was exactly 1/2 turn open from the factory.
 

hbuchanan8

"Life is Short, Ride Hard"
Joined
Oct 14, 2013
Messages
2
Location
Croton on Hudson
Can Someone help me with this god awful off idle -decel stumble. Its driving me crazy. I have done the 3/4 idle screws, the TBS and the CO adj. to 2.0 . It last about until it warms up and it starts bucking like a broke mule at the off idle position. HELP
 

Gigitt

Active Member
Joined
May 15, 2015
Messages
420
Location
Sydney Australia
Jet Tech said:
Can Someone help me with this god awful off idle -decel stumble. Its driving me crazy. I have done the 3/4 idle screws, the TBS and the CO adj. to 2.0 . It last about until it warms up and it starts bucking like a broke mule at the off idle position. HELP
Doing a TBS has to be done with a warm engine. Doing it cold will only make it smoth at cold and rough at warm

Check your hose and cap on the throttle bodies. Maybe a leak throwing it all off when you replace them.
 

midlife

Member
Joined
Oct 19, 2014
Messages
83
Location
Northumberland U.K.
This is a probably a bit of a daft question. I have a 2013 bike and had the ECU reflashed with great success. However I still find it difficult to ride smoothly at slow speeds in town etc. If I was to adjust the airscrews and T/bodies...would that muck up the mapping on my ECU?
Thanks in advance
Rob
 

The Ferret

Member
Joined
Aug 23, 2011
Messages
291
Location
North Derbyshire , UK
The TBS should equalise the air flow through each TB. The ECU mapping should adjust the injectors for a particular rev range - I think. So with a TBS you should get the same bang for your fuel.
 

SilverBullet

Well-Known Member
Joined
Dec 30, 2014
Messages
1,071
Location
Harmaston, TX
midlife said:
This is a probably a bit of a daft question. I have a 2013 bike and had the ECU reflashed with great success. However I still find it difficult to ride smoothly at slow speeds in town etc. If I was to adjust the airscrews and T/bodies...would that muck up the mapping on my ECU?
Have you removed the excessive throttle cable free play yet? That gave me a big improvement.

_
 

Funkster

New Member
Joined
Sep 12, 2015
Messages
15
Location
UK
A little bit of help please. I have a Gen 1 2013 S10 with 4000 miles. Recently I found that I was getting numb fingers through small vibrations in the handle bar. Particularly on longer runs on motorway (highway) at around 3.5 to 4.5k revs. Decided to do the airscrew adjustment and TBS. So after opening both airscrews 3/4 turn I did the TBS. The balance point wasn't far out but I still turned the left hand cylinder airscrew. Nearly all the way back to where it was originally. I decided to check whether t remains balance through the rev range. It was best between 2-3k revs and when I got it to 4k revs it was a lot further out of synch.

So thought I would take it out and the see what it felt like. Tickover the was slightly higher at just over 1k revs. It was smoother at low speed through towns, just like others found. At 3k revs it was nice and smooth. At least it felt smoother than before. At 4-4.5k revs I had the same small vibrations through the bars that gives me numb fingers (pins and needles).

So questions. Adjusting the left hand airscrew had little effect on the TBS for a 3/4 turn. Is that right?

At higher revs (4k and higher) the synch was further out. Is that normal?

The vibrations that give me numb fingers appears to be still there. What else could be causing it? Clutch basket?

Appreciate your comments on this. Thanks Funkster
 

taskmaster86

Active Member
Joined
Jun 22, 2015
Messages
328
Location
South Eastern, CT
It sounds like you did a good job balancing the throttle bodies. The only other thing I can say is to always perform the balance with the engine at operating temperature. There is no real way to balance the system at higher rpms, only at idle for now.

Your hands going numb is a very common complaint with these bikes. It has nothing to do with vibration and everything to do with ergonomics and blood flow. Handlebar risers, bars with less pull back and thicker, cushier gel style grips will all work to mitigate the problem. The issue with any of those fixes is that higher or different bars almost always requires extended brake and clutch lines. Also, no company makes a thicker, larger, softer, grip that fits the Super-Tenere yet. They are all too short and look silly.

Good luck and have fun perfecting your machine!
 

midlife

Member
Joined
Oct 19, 2014
Messages
83
Location
Northumberland U.K.
Hi Folks,
another potentially daft question!
I have bought myself a 2 column Carbtune and am wanting to build the T piece required for the left hand side. If I cut a length off the hose provided to create this, will it affect the accuracy. Or put simply,,, do the hoses to each throttle have to be exactly the same length?
Thanks in advance
Rob
 

Gigitt

Active Member
Joined
May 15, 2015
Messages
420
Location
Sydney Australia
midlife said:
Hi Folks,
another potentially daft question!
I have bought myself a 2 column Carbtune and am wanting to build the T piece required for the left hand side. If I cut a length off the hose provided to create this, will it affect the accuracy. Or put simply,,, do the hoses to each throttle have to be exactly the same length?
Thanks in advance
Rob

I just pull the hose off the Left throttle sync nipple, I have a T piece with another short length of hose
I attach the short hose to the nipple and the factory hose to the t piece. You can see it in my pic above... there is 4cm blue silicone hose and T piece connected to the nipple, and the harmonizer hose down at 7 o'clock in pic.
Now I connect my Harmonizer (carbtune or whatever) to the T piece on the left and the nipple on the right throttle body.
Start the bike, bring up to operating temp and then adjust the screws.

No the hoses do not need to exact. 10cm extra on one side will not affect the sync.
 

matbaugh

Poetry or Pragmatism?
Joined
Jul 3, 2016
Messages
44
Location
Vermont, USA
Anyone going to the CroMag Rally able to help me do this?

HI all-
Anyone going to the CroMag Rally at Silver Lake in two weeks willing/able to help me do the air screw adjustment and TBS? If you have a Harmonizer that would be excellent.
Thanks!
-Matt in Vermont
 

2daMax

Active Member
Joined
Jun 3, 2015
Messages
647
Location
Penang, Malaysia
I did my first TB sync a couple months ago. I went against the procedures outlines in the service manual, which is to not touch the right screw. I wanted to follow but could not balance up so I end up fully closing in the Left screw and adjusted the Right Screw.

Effects: More responsive on the throttle but felt that the need to be more cautious when moving from stationary. Engine died once on a traffic stop due to lack throttle. So that got me to be apprehensive whenever I had to mover from stationary.

2nd TB done recently to address the issue with the moving from stationary. I turn out my fully closed in Left screw to 180 degs and then adjusted the Right screw for the balance.

Effects: Not only is the bike responsive but felt better when moving through the gears as I shift up. Now is more forgiving from moving out from stationary. Good slow speed rideability.
 

Checkswrecks

Ungenear to broked stuff
Staff member
Global Moderator
2011 Site Supporter
Joined
Mar 7, 2011
Messages
10,200
Location
Damascus, MD
For the new folks going to do their first TBS, it will benefit you to read back through this thread. The Gen1 and Gen2 bikes are slightly different in what seems to work better. Also, do the Gen1 bikes after adjusting the CO, which is a sticky in the Power and Exhaust sub-forum.


When you post results, it will help if you post what year your Tenere is.


Thanks
 

Joto

New Member
Joined
Nov 9, 2016
Messages
4
Location
NY
Help please. A month ago bought the ST flashed by AC ( not sure which flash ) Did air screw mode and CO ( different settings ) . The bike lurks at 2000 rpm only when throttle is turned back and slowly accelerate . Lately shut off on me 4 times . Its a 2012 with 1700 miles everything stock
 

zoeed

New Member
Joined
Jun 14, 2015
Messages
25
Location
Lahore, Pakistan
Hey...
Sorry for this stupid Question.

I just ordered the bikemaster carb sync tool. Would it work?
They don't promote it for fuel i jets so wondering if this unit will work for me.
 

Dogdaze

Well-Known Member
Joined
Sep 17, 2014
Messages
3,040
Location
Solothurn, Switzerland
zoeed said:
Hey...
Sorry for this stupid Question.

I just ordered the bikemaster carb sync tool. Would it work?
They don't promote it for fuel i jets so wondering if this unit will work for me.
It will work, did you get the twin or four dial version?
 
Top