Author Topic: Re: Breva/Nevada 750 How to Throttle Synchronization Pictures Updated  (Read 28213 times)

Offline windsurfed

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Updated to include the TPS Screw Method

          2005 MOTO GUZZI BREVA NEVADA

Moto Guzzi Breva/Nevada 750. Don’t matter what you call it, its all the same: throttle plate synchronization, or cylinder synchronization, or throttle position sensor (TPS) adjustment, or throttle butterfly adjustment. Probably able to adapt this method to some other models as well.  Electronic Fuel Injections systems are much more sensitive than carburated bikes.  To start the setup you will need a very accurate way to balance the throttle butterflies. (Professionals Refer to them as throttle plates, and since I’m not a professional who cares)  I use a Twin Max electronic balancer (About $90) Very nice and very sensitive. Basically just measures the vacuumed in each throttle body.


 The throttles butterflies should be balanced whenever anything is changed, such as when the valve clearances are adjusted.  Balancing the butterflies is also commonly referred to as Cylinder Synchronization.   Always adjust spark plug gap and valve clearances before adjusting the throttle butterflies. 

The amount of air which is delivered at idle is determined by: 1. Throttle butterfly idle stop screw which holds the throttle butterfly slightly open and: 2. The idle bypass screws. The throttle butterfly idle stop position is set at the factory using an air flow bench method which precisely controls the amount of air flowing through the throttle bodies at idle.  Except in very unusual circumstances you should never need to adjust the throttle butterfly idle stop screw which limits the rotation of the butterfly toward the totally closed position.



 
There is a throttle position sensor (TPS) located on the right throttle body.

The injection system primarily uses two inputs to determine how much fuel to deliver each time the injectors open and squirt.  1. How wide open the throttle butterfly is (throttle position) 2, How fast the engine is running (RPM). At a cold start up it also uses the cylinder temperature sensor. There is no direct measurement of air flow. It is computed. (Mapped) The TPS is a variable resistor which tells the injection systems electronic control unit (ECU) how wide open the throttle is.  Since there is only one TPS, the system assumes that the left throttle body is synchronized to the right throttle body and that they are both delivering the same amount of air.

What’s really cool I think is that as the throttle butterflies begin to open, that opening is measured in electricity. (Mv’s, or Millivolts) as it opens wider more MV’s are sent to the ECU for input. Add that input and the RPM input, Cylinder Temperature input, CO2 input, outside air temp input and probably a few other inputs. The ECU analyzes all this in one cazillionth of a nano second, and that tells the injectors the exact amount of fuel to inject into the cylinders.  All this is called a Map.  The map says when the throttle is open this much and your rpm is this much, and the outside air temp is this much and all the other inputs have their say, then this is how much fuel is going to be delivered.  It takes a rocket scientist to figure all this out! Software is available to change your map should you want to or need to such as maybe when you get easier breathing exhaust coupled with a new easy air flow cleaner and so forth.  They got this down.  It’s way beyond my comprehension. As for me I will just stick to the stock apparatus. One more thing, the throttle butterfly stop screw.  Basically it just prevents the butterflies from completely closing.  If they completely close your bike would pretty much gag and puke all the time when you return to idle. These are set slightly open by the Rocket Scientists who used a mathematical equation using all the inputs and their bench air flow method. Measured in MVs precisely and not by vacuumed. This is an extremely critical measurement.  Most shops have a small Axone diagnostic computer with your Moto Guzzi model software map installed to reset your idle screw to the proper MV’s.  Or some other capable type of computer.  These little computers measure precisely at all throttle openings. But for the Idle, don’t even think adjusting the idle stop screw. 
1.  Properly connect your Twin Max Carb Balancer and calibrate.  Pretty simple, follow instructions.

 
2, Start the engine.  Bring the engine to the prescribed temperature:  *(122 degrees F 60 degrees C) No big deal on the temp.  Just thought I would throw their figures in there.
3.  Completely close the 2 bypass screws on the throttle bodies. Getting to them is a lot easier said than done.  See picture #2 also. Turn them in counting the turns until closed. Write it down. Ignore the fact that is runs worse. The Throttle bodies must be adjusted to a very fine degree of balance.

 
4.  Bring the engine to 3000 rpm +/- 300 rpm and hold
5.  Check Butterfly balance using Twin Max Carb balancer

THERE ARE 2 WAYS TO ADJUST THE (TPS) BUTTERFLIES.
 
METHOD#1 THE EASY WAY.

METHOD#2 MORE DIFFICULT BUT STILL RELATIVELY EASY. 

I PREFER METHOD#1, AND SO WILL YOU!

 6. METHOD#1=Referring to picture #2, screw the TPS adjustment screw one way or the other till the the cylinders are balanced.  Open bypass screws to original position however many turns you wrote down.  Wow, that was easy.
 
7. METHOD#2  Balance the Butterflies by first loosening the throttle body control rod lock nut, one on both sides. Then turn throttle body control rod adjuster, on vehicle left hand side, until cylinders are balanced. When finished, tighten the throttle body control rod lock nuts.  Open bypass screws to original position however many turns you wrote down.

 
Now adjust engine idle speed as follows.  Bring engine to prescribed temperature. *(158-176 degrees F or 70-80 degrees C) Adjust idle speed by means of the bypass air screws to1100 RPM +/- 50 RPM.  Bypass screws should be usually within one half turn of each other. Do them a little at a time, first one, and then the other.  I usually do them in one eighth turn increments.  I keep the twin max hooked up for this too and use this to balance at idle. If you were getting a surging when holding the throttle position in one place in first gear while going really slow down the street it is because the throttle butterflies were out of synchronization right here about idle.  I tell you, they are really sensitive. 
*The Temperature specs are for the perfect person in a controlled environment. Such as using a large fan
Blowing on the engine to keep temperature down when at idle.  I did use a laser temperature sensor just for fun to check it. Didn’t really matter because it turned out perfect.  I was soooo happy!

This “bypass” air which is not controlled by the throttle butterflies is what is increased or decreased by the idle air bypass screws. Both idle speed adjustment and idle synchronization of the 2 throttle butterflies is accomplished with these screws.  This adjustment have an effect at idle but once the throttle butterfly is opened by any significant amount the bypass air becomes insignificant.
Note:  If satisfactory synchronization of the two throttle butterflies cannot be achieved at idle using the idle air bypass screws, then something else is wrong.  There is an air leak.  Valve adjustment may be incorrect.  Significant differences in combustion chamber deposits may exist.  All of these factors will effect synchronization at idle.  However, go for a ride, see if you like the results, and if you do, the heck with everything else.
Stupid is a choice, Dumb is not a choice.  Stupid can be fixed.  Dumb cannot be fixed.

Offline fotoguzzi

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the screw you call the TPS adjustment screw should be called the balance screw as it syncs the two butterfly plates.. I would never change the length of the control rod (as stated in version #2) The idle stop screw on the TB side is used to set base TPS value and it can be off from factory.. to set TPS (before balancing) you need to screw the idle stop screw (on the TPS side TB) all the way  out and then read voltage from TPS, on big twins its should be around 150Mv fully closed. setting TPS is done by rotating the TPS unit in the throttle body.. then disconnect the connecting rod, turn Idle stop screw in to reach idle TPS value (525Mv on big twins).these  steps can be done w/motor off- key on. thats when you rehook up the balance rod and start motor, turn balance screw to bring the other butterfly into balance. finally increase idle to 1200 and balance with the air bleed screws.
if your instructions are followed you'd have no idea if the base TPS setting is correct and therefore could have too high or too low  signal from the TPS and thus run rich or lean at idle and thruout the rev range.

MINNEAPOLIS, MN

iamz

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Thanks for the detailed documentation Windsurfed.  :)

guzzilady

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Yes, thanks for the detailed information. I predict Eric and I will be tackling this on my Breva in the future.  :)

Wildguzzi.com


T.B.

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why do you have to close the air bleed screws when you do the sync? 
« Last Edit: August 04, 2008, 01:30:07 PM by T.B. »

Offline Pfaff!

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I just learned that the 750 Breva are NOT equipped with the M15M ECU but the M15RC, meaning that TPS can only be set electronically from the Axone or the VDSTS PRO version - not the standard version - which I have got  :-\.

Anders Holt

Breva V 750 ie "Rossinante" '03. Running fine ever since. Sold.
Pushing bikes these days.

"El camino amigo, el camino y nada mas"

Offline NOLAGuzzi

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I just learned that the 750 Breva are NOT equipped with the M15M ECU but the M15RC, meaning that TPS can only be set electronically from the Axone or the VDSTS PRO version - not the standard version - which I have got  :-\.



SH*T. that is no good, if true the standard version is only good for getting the error codes. :-[
04 Breva 750
NOLA = New Orleans LA

Offline Eric

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Does anyone have a comprehensive list of what either versions of the VDSTS software can do with what model Guzzi? There's a general list available for all bikes but some features are supported in some ECUs and others not.
07 Norge
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Moorhead, Minnesota

Gone: 2005 Ural, 2011 Ural, 2003 EV, 2005 750 Breva

Offline fotoguzzi

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sure looks like the same TPS as my two bikes (15m & P8 cpu)  and it is adjustable manually if it has slotted holes in it.


MINNEAPOLIS, MN

Wayne Orwig

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sure looks like the same TPS as my two bikes (15m & P8 cpu)  and it is adjustable manually if it has slotted holes in it.

Pretty sure it does NOT have the slotted version.

Offline N97972

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Re: Re: Breva/Nevada 750 How to Throttle Synchronization Pictures Updated
« Reply #10 on: August 04, 2008, 09:14:16 PM »
sure looks like the same TPS as my two bikes (15m & P8 cpu)  and it is adjustable manually if it has slotted holes in it.

Pretty sure it does NOT have the slotted version.

Interesting,  just checked our 3 'o5 small blocks... none of them are slotted.. but they do have a dab of yellow paint on each
screw... what gives??
Cashmere
'70 150K
'46 Stinson 108-1
78 R45/N
03 EV
04 R1200C
05 Breva
05 Nevada
05 Triumph Bonnie America
05 Honda Shadow Aero
2 honda rebel s

Offline Pfaff!

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Re: Re: Breva/Nevada 750 How to Throttle Synchronization Pictures Updated
« Reply #11 on: August 05, 2008, 02:55:36 AM »
Does anyone have a comprehensive list of what either versions of the VDSTS software can do with what model Guzzi? There's a general list available for all bikes but some features are supported in some ECUs and others not.

We're having a little conversation 'bout that over on Guzzitech board. No solutions yet, tho', but I'll be back here when a good answer is available.  ;D

I just learned that the 750 Breva are NOT equipped with the M15M ECU but the M15RC, meaning that TPS can only be set electronically from the Axone or the VDSTS PRO version - not the standard version - which I have got  :-\.



SH*T. that is no good, if true the standard version is only good for getting the error codes. :-[

So it is with the 15M version. But there might be a standard 15RS version too. Hopefully.  :-\
« Last Edit: August 05, 2008, 02:58:14 AM by Holt »
Anders Holt

Breva V 750 ie "Rossinante" '03. Running fine ever since. Sold.
Pushing bikes these days.

"El camino amigo, el camino y nada mas"

Offline Pfaff!

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Re: Re: Breva/Nevada 750 How to Throttle Synchronization Pictures Updated
« Reply #12 on: August 07, 2008, 11:33:11 AM »
So it is; a 15RC ECU on the 750 Breva.

Worth noticing, if you're going for a VDSTS.

Anders Holt

Breva V 750 ie "Rossinante" '03. Running fine ever since. Sold.
Pushing bikes these days.

"El camino amigo, el camino y nada mas"

Offline NOLAGuzzi

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Re: Re: Breva/Nevada 750 How to Throttle Synchronization Pictures Updated
« Reply #13 on: August 07, 2008, 03:32:43 PM »
Holt,
The 15RC is the ecu recognized by my VDST software, at least thats what it says in the lower right corner. I am still running version 3.02 in windows XP and I can reset the TPS with the software.  Did you get the 15M on purpose?
04 Breva 750
NOLA = New Orleans LA

Offline Pfaff!

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Re: Re: Breva/Nevada 750 How to Throttle Synchronization Pictures Updated
« Reply #14 on: August 08, 2008, 01:19:32 AM »
Holt,
  Did you get the 15M on purpose?




Well. Sort of, I guess. Probably just asked for the one suiting the 750, but I've had it on the shelf since last fall and never used it before.
The right software/cable should do the trick...  :-\
Anders Holt

Breva V 750 ie "Rossinante" '03. Running fine ever since. Sold.
Pushing bikes these days.

"El camino amigo, el camino y nada mas"

sorinpetrila

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Dear windsurfed. Thank you for this post. Without this information you shared, I couldn't be able to solve my problem. I post this in case someone have the same symptoms. First video is before sync. It was very wrong adjusted I guess by the previous owner.

The idle was low (800-900) with gaps.
At neutral it stops in 1-2 minute ...especial at red light in the street.
Some vibration extra , compared with synchronized adjust.


Moto Guzzi Breva 750 issue video1:
http://www.youtube.com/watch?v=Ag1ag_oQu7w

Image synch:
https://plus.google.com/photos/112056727697058144354/albums/5872131745443721601/5885604422198780706?banner=pwa&pid=5885604422198780706&oid=112056727697058144354


Moto Guzzi Breva 750 issue solved  video 2:
http://www.youtube.com/watch?v=ptsmnqiOIAA

The idle increased. The power increased. I hope the consumption will decrease.

Hope to be usefully for other user with the same problem as mine.

Sorry for my English  :BEER:

Offline sign216

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    • Guzzi 750s - Breva, Nevada, V7, etc
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Glad you got your bike adjusted.  Balanced throttle bodies is a big help to smooth running.
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https://groups.io/g/Moto-Guzzi-750

Offline rathlindri

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I acquired an '07 Breva 750 with only 11k miles on it in recent weeks.....just wanted to say what a useful guide this is....thanks for posting it up....transformed my 'bike (method 1)

Offline windsurfed

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thanks,  hope you enjoy the bike.  I have over 40, 000 on mine and have had only minor issues.  Its a 2005 and I bought it brand new.   
Stupid is a choice, Dumb is not a choice.  Stupid can be fixed.  Dumb cannot be fixed.

Offline scra99tch

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How would you get back to baseline if you did indeed mess with the Throttle Butterfly Stop Screw?

I was helping a friend out and after reset we noticed the TPS was at 3.1 so we turned the stop screw in till it hit 4.73 and again I hit reset this time it went back again to 3.1 degrees.  So I had him back it all the way out and hit reset again and then with that screw turned it in till TPS read 4.73. 

I now notice that to get the proper millivolt we would need to turn the hex/slotted screw instead of the allen butterfly stop screw.

1974 Eldorado
2007 California Vintage

Offline dera

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Re: Re: Breva/Nevada 750 How to Throttle Synchronization Pictures Updated
« Reply #20 on: January 07, 2015, 12:01:04 PM »
Hi there!
Is it possible that someone creates such an instruction for Quota 1100ES? :-)
It would be great...

Best Regards,
Michael
California Über Alles

 

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