Re: Crossover Tube

[Ben Barkow <dr.ben@xxxxxxxxx>]

Tom -

If your syching is spot on, and no doubt yours is, the balance tubes would
have little effect. Have you tried the pinch test later on when gremlins
have dysbalanced the TPs?

What "vacuum tubes"? Are there radio tubes in an Oilhead? More seriously,
are these downstream of the butterflies because that's the induction realm
of interest for balancing?

Of course balancing to a fare thee well has no influence on pop-back
(perhaps a symtom of leanhood), and not perfectly clear to me how pop-back
is related to the ECU's activities implicated in surging (yes, I know I said
"lean," but closing the throttle fast is a transient while O2 action is
steady-state). I suppose the general issue is broad-scope leaness at many
points of operation.

My machine (shiny black 1999 R1100S) had no cannisters from the PO so I
don't know about that circuit.

Sorry to be re-inventing the wheel or failing to do my homework. I use the
best judgment I can about asking dumb questions versus lurking. I think
given the variation of opinion I've heard to some of my possibly
insufficiently homeworked questions, it was fair to ask them. Indeed, given
some of the responses I've read, perhaps even beneficial. Some members were
glad to hear how you deal with cannisterectomies.

In response to Bob Hadden, I would repeat my initial post comment that
butterflies are open a pretty small amount a pretty large percentage of the
time and to influence balance you don't need a whole lot of make-up mix (or
to tweak the bypass screw much). Having spent much time gazing at the
White-Out marks on my throttle grips while doing carbs switcheroos (marks
that indicates the rotation of the throttle), I can tell you that
butterflies and slides are open rather small amounts even when running 90
mph.

Ben


> Ben:
> 
> I've done cannisterectomies before.  Removing the charcoal cannister on the
> back of the bike.   You can do it by removing the tubing completely and
> capping the vacuum outlets on the throttle bodies or you can leave the rubber
> tubing in and change the routing so it simply connects the two sides.    This
> is the way I do it now because it's easier to do and easier to put back.
> Also, you don't need to be concerned about plastic caps falling off.  The
> rubber tubing really stays on.   I've not noticed a big difference in
> performance or smoothness by connecting the two sides or mearly capping them
> off.
> 
> The stock system connects the two sides through the vacuum tubes as well.
> 
> If you read the mounds of information available on these subjects, you'll get
> a much better idea what does what.    Seems like your trying to reinvent the
> wheel here.
> 
> Best,
> 
> - -TB
> 
> Now with carbs, makes sense to me to have the largest feasible cross-over
> pipe between the carbs as that helps average the two

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