Intake fab

I am going to fabricate intake flanges, hopefully tonight. I picked up most of the hardware I will need at lunch today, namely some 2″ wide bar (I got 1/8″ thick, though I was hoping on 1/4″) and some 1″ pipe.

Each flange is basically going to be an appropriately shaped base, with mounting holes drilled in the wings and a large hole in the center. I will cut a short piece of the pipe, fit it to the hole and braze it in place. After grinding/filing/brushing them to finish, I will cut gaskets to fit and bolt them to the engine intakes.

I found neoprene plumbing reducers of a suitable size to interface between the intake flanges and the throttle bodies. They are only $4 each, as opposed to $12-$20 each for silicone. Assuming it all works, I will probably replace them with spiffy pretty silicone ones later, but these should do fine for getting Buzz running again. In either case, the rubbery reducers should allow enough flex to account for the spacing differences between the intake tracts and the throttle bodies.

I salvaged my fuel pump from an in-tank unit purchased on eBay. The in-tank design has pump, pressure regulator and surge tank (as well as fuel level sensing) in one simple unit, but the whole unit could never fit in the Maxim’s tank. I will have to plumb these pieces together externally. At this point, I have all the tubing I need for hooking up the fuel pump, but I’m short a T to connect the regulator. The regulator basically relieves overpressure by bypassing the excess back to the tank. I need to feed the output of the pump to the T, then connect one side to the throttle body and the other to the regulator. The regulator’s bypass port will be sent back to the tank, which will require adding a return path. I think I can use a weldless bung for that connection. If not, I will need to make the tank safe for brazing heat. This can be done by rinsing it with soapy water and once I’m ready to do that, I may as well apply some tank liner, too.

It looks like I will have to fabricate a trigger wheel for my EDIS ignition. There is a company in Britain that sells laser cut ones that would probably fit, but it gets expensive fast. Surely, there is a domestic manufacturer of such things? For a motorcycle, it needs to be a small unit, probably no more than 3″ or so. The smallest from DIYAutotune is 4″. Maybe I need to cut a deal with eMachineShop.

I need to stop for the T and some brazing rod on the way home tonight. I will also get a fire extinguisher or two, for beginning probably this weekend, I will be working with liquid fuel under pressure.

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