BMW R65 Restoration - Part 6 - Handle Bars, Carburetors, Chokes, and Throttle

Greetings friends,

This is a continuation of my series of posts documenting the restoration of my BMW R65. For the previous post in this series, click here.

Today we're going to jam a lot of small steps into a single blog post. In the last post I mounted the engine and transmission into the frame of the bike, and today we're attaching most of the peripheral equipment that the engine needs to run.

Let's start with the carburetors. These guys were in pretty good shape, and as far as attaching them to the engine, they were surprisingly easy, as there's a rubber sleeve that clamps onto the carb, connecting it into the intake of the corresponding cylinder. The backside of the carbs have fittings to allow the throttle cables and choke cables to be attached, and a small hose barb for the fuel line. We'll touch on each of these as each is installed. As part of the restoration/modification of this bike, I'm going for somewhat of a "Cafe Racer" style, which commonly uses pod-type filters on the carburetor inlets, which can be seen below. The filters mounted with a rubber sleeve exactly how the carbs mount to the cylinder.

The airbox that came with these bikes was pretty ugly in my opinion, so at least for now I'm forgoing trying to find a used airbox and simply eliminating it for the individual filters, and covering the top of the engine/starter motor with a nice cover. There is much debate in the community surrounding the impact on the engine of pod-filters vs airboxes, but for the sake of simplicity this is what I'm doing for now.

Pod filters fit right onto the carbs!

This motorcycle was originally equipped with choke cables that were manipulated with a knob mounted on the handlebars, but for an overall cleaner as less-cluttered look, I decided to forgo the cables and use "Choke Pull Tabs" instead. These tabs are thin wires connected to aluminum knobs that attach directly to the carburetor and allow fast choke (dis)engagement. The only disadvantage to the tabs is that each one needs to be pulled by itself, whereas the original choke cables would have pulled both chokes simultaneously. This isn't an issue since it's quite easy to stop for a sec and pull them to disable the choke.

It's obvious where to pull, right?

The handlebars I'm installing are unpainted stainless steel, as close in dimensions as I could get to the originals (22 mm dia.). They bolted on very easily, so there's not too much to discuss surrounding their installation.

The throttle body was a relatively cheap amazon purchase, and was a very simple fit over the end of the handlebar. The rounded end caps of the handlebar are tack-welded on, so I had to grind that back a bit to accommodate the throttle body. I lubricated the throttle body with the green grease I used for the steering bearing in a previous post. 

I purchased a throttle cable kit, which included all the necessary fittings to cut to length and assemble my own throttle cables. Using the old throttle cables as a reference, I cut the wires to length and assembled them in the same manner as the old ones. The old cables use a splitting assembly to allow one cable from the throttle body to control both butterfly valves at once. The kit I bought included this splitter, so I was able to recreate the original cables almost exactly.

   

Completed throttle cables. I forgot to take a pic of the
originals before I disassembled them...

Once the cables were fully assembled, routing them from the throttle body through the frame was simple, and the cable ends slipped nicely into the provided throttle levers on the carburetors. The levers are tucked away behind the carbs, but I'll include a picture in a different post to show them.

A little too zoomed-out, but here you can see the starter cover/airbox eliminator.

The handlebar grips were very easy to install thanks to a pro-tip from a friend of mine. Wetting the inside of the grip and the handlebar with isopropyl alcohol (IPA) allowed the grips to slide on very easily, and after the IPA evaporated overnight, the grips were super solidly in place. I did the same thing for the footrests!

There are a number of other accessories that will ultimately bolt onto the handle bars, but I think those will best be covered in a separate post. The engine electrics will also be covered separately, so for now, that's all!

Thanks for reading,

Juju

P.S. For the attentive readers in my audience, yes there are components installed on the bike that haven't been covered by this series of posts. I work on the bike as I go, and select parts to write about, but those don't always match chronologically...