[gpineau]

This is stepper motor driven. I have managed to control it from firmware. I have calibration routine that finds the full open and closed positions and remembers them. Then it can position the secondary plates at any point between the open and closed points. It uses a look up table based on TPS and RPM to decide the percent of the opening.

http://gpineau.com/CYCLE%20FILES/20201216_170651.mp4

[gpineau]

I pulled the carbs and doing a test fit to see if it is all going to work. Everything looks good and it will have enough clearance to get clamps on.
https://youtu.be/tAgiSxinQm0

[PSIG]

[gpineau]

OOPS ! brain fart....
Not the worst idea I have ever had but pretty close. Pouring liquid silicone down the throat of a throttle body and not expecting it to find every leak possible. What was I thinking. Turned into a gooey mess and went everywhere but where I wanted.

Decided on another approach. I will make a 3D model of the gasket (4 copies) then make a mold for them in a sealed container ,, then I can cast the real gasket out of silicone and it will be a much better fit that what I started out to make.
The boot mold takes 7 hours to print and will probably be destroyed removing the boots but It is necessary to make a good seal.

[PSIG]

Could it be a matter of wrapping the stubs with a few layers of self-amalgamating (self-fusing) silicone tape to the perfect size?

[LPG2CV]

I don't suppose the silicon would be strong enough to support the TB's if you made the whole connector from silicon!

[gpineau]

Psig, self fusing tape came to mind but the problem is that there needs to be an offset to one side. There is a coolant pipe that exits the head between the ports. The problem I was trying to avoid was if everything is centered there is not enough room for the boot and a clamp. On the last one I assembled it outside the bike then ground away on one side until it would fit between the coolant pipe and the cylinder port. And that was a real pain. I had to drive the clamps over the boot with a hammer and chisel. You probably can't see it but inside the mold there is one side that is flat and that is the side I want to face the coolant pipe.

I may end up force fitting it like I did the first one.

[gpineau]

The mold turned out really nice. I hope I can get it out of the printer without breaking it.

[PSIG]

Ah, I didn't see the flats you made for clearance. If you find no joy; what is the carb/TB spigot O.D. and the head spigot O.D.? What is the overall length of the boot coupler?

With that info (and if you like) I can check some sources of silicone couplers/adapters for a tapered piece that would be reinforced construction like the originals, and that would clear without the extra thickness needed to adapt a straight boot.

s-l225.jpg (14.88 KiB) Viewed 4317 times

[gpineau]

The boots will be ready to pop out of the mole in another hour but if you can find a one piece solution,,,That would be great.!
The throttle body OD is 53.55mm the depth is 13mm.
The head OD is 45mm and the depth is 13mm.

Found a reducer on Amazon 1.75 to 2.0 BUT $20 EACH!
Found same on aliexpress for$6.25 each. Ordered 4 for$30.
My little boot didnt turn out half bad but still has a clearance problem. I will need to file down one side of the outer hose to make it fit. That will work for now. I expect my China shipment at the end of Jan.