|Pete Murphy renews a pair of carburetors, part II|
|I fitted a
vacuum tuning port for balancing the carbs. It's been
covered a few times already but here's what I used and
how I did it. The one with the little red condom is my
back up if the port doesn't work. The item I used is a
little air valve. Not sure what its intended use is. I
found it on Beijing Lu in Shanghai where I live. It had a
conical thread but the back up has a parallel thread so
first thing was to gently file and re-thread the one I
used to the same as the back up in case it doesn't work!
There's some handy casting marks showing the centre so getting the hole in the right place wasn't too hard.
The hole is scary big!
It's a big hole if I mess up! Thread was unusual. I think it is Whitworth (?) pipe G 1/8 28.
Valve fits yeah! - permanent marker on the unwanted protrusion
Shaped the end
Threaded the existing nipple
finished item fitted to carb - I think I'll shorten the new hose nipple (is that what it's called?) maybe half what it is now. I need to find a bung or cap for it too, so I'll wait til I've found that.
I think it looks factory fitted, no? I'm happy with it anyway. Gonna flow test them before final fitting to make sure they both work the same. I'll locktite the threads too.
I know it's obvious but just to be clear - the new pipe nipple was cut off the triple pipe thingy (actually a slightly different one - I'm making another set at the same time) and internally threaded. forgot to take a pic. I'll add a pic when I thread the next one.