My v-stack experiment appears to be a success. The stacks were modified to fit the filters. I only took a few pics, because I was more interested in riding the thing than admiring my work.
Basically, a pair of Mikuni RS 50mm velocity stacks were de-horned to fit inside of a new set of UP-4229 filters. I don't run Uni's dry, so they got a light coating of Uni foam oil, outside only, & that was blotted off. I used a combination of free-hand hacksaw, Dremel grinding, and hand-filing to remove & shape the horns.
Here's a pic of the horns removed:
The end result has a 41mm stack length; since the v-stack horns were removed, they are functionally more like snorkles than true v-stacks...no matter, it extends the OAL of the intake tract, which is what I wanted.
This is a close-up of the v-stack mounting flange with the stack inside the filter & the clamp removed:
Here's a pic of what it looks like inside the filter:
A couple of more views of what the starboard side looks like mounted when mounted up; note the limited clearance to the sidecover mount:
Side view:
Back to back test runs in similar weather with & without the stacks showed that the 4900 - 5600 rich dip is gone, & overall things are leaner at idle & cruise, and the above-mentioned rich band is gone.
With this set-up it appears that I can now run pure gas. Gotta test that theory.
Time will tell what the dyno has to say, however once I run the bike in different weather conditions, try pure gas or a pure-gas blend, & check the carb-sync, its off to the dyno for measurement.
So far, I like this v-stack mod.
