Hello, my 750 DP plays up when the car has been sitting for a month or so, it spews fuel out of the air pipe (I think, 8mm pipe cutoff at 45 degrees pointing upwards on the primary side. After an engine fire today I decided it needs fixing. Once the car has been driven it's good for a couple of weeks oddly enough.

I pulled the carb apart and found the power valve is a solid blank, has anyone seen this?
I replaced the needle/seat's and set the float levels and put a power valve in it, (there are two power valves in the kit, are they different?). The car starts easier than before and runs good, maybe has less power at high revs.

The primary metering block is a purple anodised aftermarket unit, secondary's look factory.

The engine is a big cam high compression thing, I bought the car as it is and have no history.

A lot of questions here, can anyone shed some light?