Carburetor back on

And yes today I installed the carburetor again onto the engine.

Yes it looks to work just fine!!!!

There is one interesting initially a bit confusing feature though.
During the throttle range from 0% to 80% or so, you need to adjust the mixture control, like you would expect. More air, more fuel.

But at the highest throttle setting, the carburetor opens a second channel, see diagram below, and suddenly leaning of the mixture hardly does a thing. Like its not killing the engine, but you still hear it revving up a bit from 1500 to 1600rpm.

The acceleration pump is controlled by the throttle, and when the throttle is open very quick, extra fuel is “pumped” into the main discharge nozzle and into the air stream.
But when just opening the throttle slowly or at any speed really, the pump piston with the two pins on top (see diagram) gets pushed down, opening a hole you can’t see on this diagram, allowing extra fuel into the main discharge nozzle.

1405540445

So yes, the initially confusing behavior is correct. But because I still need to lean of the mixture all the way to 0%, maybe I need to get a smaller jet, the left one.
Now reading the carburetor findings from Wed 9 Jul 2014, I noticed that the fuel pump jet is already smaller then what’s on the id plate on the carburetor. I wonder if the previous owner has been “playing” with this to get full throttle mixture rating correct.
From what I see here it looks like that jet is still a bit to big.
I will have to talk to some people about this !!!!

BUT LOOKING GOOD NOW.

So after my initial engine testing, I started taxing the Bleriot. Went up and down the taxiway twice. All went really well. Could steer really well !!!!
When I came back I did another engine test, and it still goes to 1600rpm. Total engine time was 0.9 hour.
Because I am running the engine a lot leaner then before, the spark plugs aren’t “flooding” anymore, and because of that the engine runs on all 5 cylinders now.

SO READY FOR THE NEXT FAST TAXI AND HOPEFULLY FLIGHT  🙂

Leave a comment