The XS Triple Sidecar - gets some second hand GSXR 750 flatslides

The plan is simple: Take carbs from an inline-four, remove one carb, put it back together, job's a good un'. Yeah right. What you see is a week's worth of work.

So I started off with a set of perfectly good GSX-R 750 carbs.

Removed the rails and the right-most carb to get a feeling, if and where the carb bodies needed to be modified and if maybe the stock throttle shaft could be repurposed.

This would have been my preferred placement for the throttle cables and idle-adjuster as they would have been perfectly accessible...

... and perfectly in the way of the fuel tank.

So shuffled the carbs around, ran the throttle cables through the frame. (Thanks Yamaha for placing this opening in just about the right spot!)

With the carbs laid out and all clearances checked, the carb spacing was finalised (88mm for those who want to do similiar things) and 15x15x2 stainless L-profile was drilled.

And it turns out there's just one spot, where things get a bit tight. Removing about 2mm from this fuel-line boss was all it took to make them clear.

In order to get the spacing on the bottom rail right, the throttle-shaft (10mm) was cut from a bit of stainless. (Stupid idea, more on that later.)

The bottom rail was then laid out and pockets milled out for the mixture-screws and the profile shortened on the engine side, so access would be a bit easier.

Drilling stainless is a royal pain. Even more so, when you have a slightly worn out Chinese drill chuck, which has got a bit of a death-wobble to it. (Unfortunately my good chuck won't grip drills smaller than 3mm and the one in the picture is a 2.0mm one...) So it broke off flush with the shaft.

Nevermind, got it out and went ahead tapping the shaft...

... bugger.

Then I went to my metal supplier and got an offcut of silversteel, enough for two carbs. Let's just say I am happy I did and the following pictures show me working with the material for the second shaft made from silversteel ...

Old machinist's trick here on how to find center, if you don't have a DRO on your mill (or want to do it quicker with just a long metal ruler) - once you've found center the ruler will be perfectly parallel to the mill's table. The longer the ruler the more accurate the measurement.

Throttle assembly is off a DR600, including the cables. These are actually bits I bought many years ago for my XT500.

And that's the carbs more or less finished. (Chokes missing in the pictures below, also the idle adjustment needs some quality time with my lathe and of course the whole lot has to be synced.)

Installed.

This is the actual second start of the XS with the carbs installed. No sync, no idle adjustment, nothing and she just purrs like a kitten.

What's left to do: Fix the idle adjustment, sync the carbs and then probably throw the O2-sensor on and see where we're at. First testride (regardless of mal-adjusted carbs) has shown a substantial increase in low-end torque, which is all this exercise has been about.