Throttle body link

[Bison]

Hello Folks,
So, riding along towards Glasgow on the motorway on Big Bertha my Norge, and she cuts out, in the outside lane of course, but I manage to get into the emergency lane. She was idling no problem, but wouldn't respond to the throtte, TPS connector thinks I, so when I have a look I find the plastic socket on the long rod that connects the throttle bodies has popped off on one side, hhhmmm, I pop it back on and away we go, until a few miles later when it pops off again, tying wire to the rescue!. Turns out the plastic socket is worn, even though lubed, ho hum. Gutsibits didn't have one, so I've sourced one from and engineering shop, 8mm ball, 5mm thread. So, of course, if one alters the position of this socket ones underpants will immediately burst into flames and self destruct. I intend turning up two small pins which fit into the existing sockets then attaching them to a flat rod and adjusting to get a close position, then adjusting the rod to the dimension of the original, but after that?, what to do?, how can I adjust the LH throttle body to closely match the 4.7 degrees of the one controlled by the TPS, or do I just have to hope for the best?.
Thanks in advance
Alan.

[paulbricey]

I don't understand why there's a problem ??..  Basically one side is calibrated to be at 4.7 degrees in factory & that's the one you reset with Guzzidiag etc. The linkage that joins the two so that they are 'synchronised' is adjustable/adjusted so that the two cylinder vacuums are balanced at same guage/manometer reading.

Changing the linkage pivots just means you have to 're-balance' the vacuums because the linkage may be slightly different length. You just use the same procedure & same big adjustment screws (NOT THE SACRED SCREW) to balance the TPS.

[Tom H]

You don't need to worry about the TPS side, leave it alone.

All you need to do is check the balance of the TB's with a vacuum gauge or manometer to make sure they are even at idle and just off of idle.. You would only need to make an adjustment to the new linkage you added provided the air bypass screws were fine before the new linkage.

Tom

[Bison]

Sounds good, thank you.

[Huzo]

But wait…there’s more.
The overall length of the ball to ball distance must not be varied, so make sure the centres are the same as original.
This is because the two actuating arms on the TB’s must act as a parallelogram (if you get me…).

Hold your two hands in front of you edge on and make them parallel. If you rotate your wrists 20 degrees, your fingertips will move the same distance horizontally. But if your hands do not start from parallel then your fingertip horizontal distance will not be the same when rotate that 20 degrees.
Please just trust me.

The left TB will always come to rest on the sacred screw and it is the bell crank adjusting screw that must be used to bring the right TB into balance by manometer, not manipulation of the bellcrank linkage length.
Note that when you refit your new bellcrank linkage, the TPS will be out, but with Guzzidiag, re set it to 4.6 - 4.7
  Then go ahead and re do the high speed (3,000 rpm) balance.

[Huzo]

I don't understand why there's a problem ??..  Basically one side is calibrated to be at 4.7 degrees in factory & that's the one you reset with Guzzidiag etc. The linkage that joins the two so that they are 'synchronised' is adjustable/adjusted so that the two cylinder vacuums are balanced at same guage/manometer reading.

Changing the linkage pivots just means you have to 're-balance' the vacuums because the linkage may be slightly different length. You just use the same procedure & same big adjustment screws (NOT THE SACRED SCREW) to balance the TPS.

If the linkage is different length, then the rate of change of plate opening with throttle application will not be the same on both sides.
The linkage MUST be made to the same length after the modification, as it was before.

[n3303j]

Basically, if you wind both throttle plate atop screws out so that both throttle plates are completely closed the linkage must be a correct fit.
Close the air bleed screws completely. Then set your open angle on the TPS side and the other will match. Check it for synchronization with your manometer before opening air mix screws. Do any synch adjustment to the side without the TPS. A careful look at the linkage will show what screw has to be tweaked. After synching vacuum start opening air screws to get the required idle speed. Use the manometer to maintain sync only touching air screws. When you have your idle speed correct you should be ready to ride.

[Bison]

Ah, so this makes sense of why I read you must not alter the length of the connecting rod with the ball joints, in other words, don't break the yellow paint seal on the lock nuts,  and is also the reason I posted.
Thank you all.

[paulbricey]

The linkage length CAN/DOES change slightly as long as the length difference (as measured by vacuum difference) is adjustable using the 'set screw on the throttle body connecting rod'.   The connecting rod is attached to the 'reference throttle body' VIA the adjustment mechanism.

[Wayne Orwig]

It is the idle stop screws that are 'do not touch'. The linkage distance sets the high speed sync and can be adjusted as needed. Do not touch the idle stop screws but instead adjust the air bypass screws as needed for idle sync.

[n3303j]

Have to back off both idle stop screws to to completely close throttle plates to establish base position before setting connecting rod length and then set initial throttle plate angle via TPS voltage reading.

[Wayne Orwig]

Have to back off both idle stop screws to to completely close throttle plates to establish base position before setting connecting rod length and then set initial throttle plate angle via TPS voltage reading.

That is what you do on a Tonti or Spine frame.
You do that on a CARC bike (Norge), you just messed them up. Never touch the idle stops on a CARC frame.

[n3303j]

That is what you do on a Tonti or Spine frame.
You do that on a CARC bike (Norge), you just messed them up. Never touch the idle stops on a CARC frame.

So then the throttle plate angle is factory set and if installing a TPS you'd just adjust it until the voltage read correctly?

[Wayne Orwig]

So then the throttle plate angle is factory set and if installing a TPS you'd just adjust it until the voltage read correctly?

There is no TPS adjustment on a CARC frame bike. You install the non-adjustable TPS, hit RESET on the software, done. Since the factory idle stop throttle angle is sacred and not to be touched. If you touch it, you opened a can of worms for sure.

[n3303j]

I'm learning something every day. These modern bikes are going to be the end of me. I'm at Barbers Vintage in Alabama in my V11 and pulled out of their lot to head back to the motel. (1,200 miles from home). Hit about 60 and the bike dies. Long story short the fuel pump connector decided to give up conducting and shut off the pump (1.5 hours diagnosis on a hot Alabama highway. My T3 would have never done that to me! Bad EV! Oh well, cut out the connector and spliced the wired and problem is gone. Going to autopsy connector to nite. Slowly heading north to Massachusetts starting tomorrow.
Thanks for the enlightenment about CARC.



The culprit has been revealed. Fuel pump plug innards.