I stumbled across
this blog while searching for something else and, since
I had some K75 and K1100 TBs on hand, I thought I'd give it a
go. Despite the claim that the K1100 TBs are 3mm
larger in diameter, I measured the butterfly discs when I
had them apart and the difference in diameter is actually
only about 1mm. This yields only a 6% increase in TB
cross-section area but, since it's a "free" mod for me, I
figured it was worth trying out on my K75 Frankenbrick.
Every little bit helps, right?
Here's the two sets of TBs I
started out with. One from a K1100 and one from a K75:
The K11 TBs have a vacuum hose
across the back attached with Oetiker clamps. I cut those
off with a Dremel cutting wheel and, since that hose is
superfluous on a K75, I'll cap them off with some 1/4"
(7mm) plastic caps from the hardware store.
Then I removed the #2 TB from the
K11 TBs, slid the #1 TB back and cut off the excess at the
ends of the mounting
brackets at the front:
The shaft that drives the TPS on
the K1100 is flat at the end while the shaft that drives the
K75 TPS is longer and semi-circular. In order that swap those I took
the nut/washer off of each of the rear butterfly shafts and then
removed the butterfly discs. The little brass screws that hold
the disk in the shaft are tough little buggers to break free
so I had to use a good small screwdriver and lots of
pressure to get them out, especially on the old K75 TBs.
And here's the final product with
a 2V TPS installed:
Since my Frankenbrick already has
a K1100 front end and throttle assembly with a K1100RS
throttle cable, there shouldn't be any problems with the
different throttle cable attachment. Although I may need to
switch from a K1100RS cable to a longer K1100LT cable for
I probably won't get around to
actually installing them on the K75 Frankenbrick for a while
as I have other things on my plate but I'll come back and
update this page when I do.
© 2013 Drake Smith - Please do
not use or reproduce this elsewhere. Feel free to link
to it though.