Fuel Mixture Lever

[Captain Orso]

The manual states that it's there, but not how to use it.

 

Per default it is set to Rich (lower position) and there is no Cut-Off position (Cut-off is per plunger-press per engine behind the pilot's seat) and the upper position is Lean.

 

The is no problem to starting the engines without touching the Fuel Mixture lever, and I've not read anything to the contrary.

 

I believe I read something on a checklist that you can set to lean for optimal long-range cruising, but there's nothing in the manual.

 

So how am I to use the Fuel Mixture lever?

[fjacobsen]

As You said Yourself...

 

To lower fuel consumption on long range cruise - set it to Weak.

Just note that the limits for Boost pressure and RPM are lower.

[razo+r]

In cruise, lean

 

In any other scenario, rich.

[Captain Orso]

Thanks for the replies, guys.

 

8 hours ago, razo+r said:

In cruise, lean

 

In any other scenario, rich.

 

8 hours ago, fjacobsen said:

As You said Yourself...

 

To lower fuel consumption on long range cruise - set it to Weak.

Just note that the limits for Boost pressure and RPM are lower.

 

Are those given operational limits, or simply that the engines won't run at higher RPM's because there is simply less fuel being fed to them?

[gabuzomeu]

When the mixture is lean, temperature in cylinders is higher so the engine would knock/detonate at lower power ( manifold pressure).

So you risk destroying the engine if pushing it.

 

 

[fjacobsen]

Running Engines with Rich mixture, helps cool the engine due to the excessive amount of fuel.

Running Lean (Weak) means less cooling and thus You can´t push the Engines as hard.

Edited September 24, 2021 by fjacobsen

[Captain Orso]

Thanks for the replies. I hope they publish some limits on which to orient.

[TWC_SLAG]

In general aviation twins, the procedure was to lean out the mixture as the cylinder temp goes up, and then back off slightly when the temp starts to fall.  I wonder what the procedure was for the Mosquito.

 

Also, there was a mixture lever for each engine.  But, I see only one lever on page 74 of the flight manual.  So, that lever was for both engines?  Strange.

[Art-J]

12 hours ago, TWC_SLAG said:

In general aviation twins, the procedure was to lean out the mixture as the cylinder temp goes up, and then back off slightly when the temp starts to fall.  I wonder what the procedure was for the Mosquito.

 

Also, there was a mixture lever for each engine.  But, I see only one lever on page 74 of the flight manual.  So, that lever was for both engines?  Strange.

 

Not that most warbirds of that era (pretty much all on US, UK and German side) went away from manual mixture adjustment as you described and were equipped with mixture regulators providing only fixed positions (for example auto-lean, auto-rich, auto-emergency-rich, cut-off, run and various combinations of these).

[TWC_SLAG]

1 hour ago, Art-J said:

 

Not that most warbirds of that era (pretty much all on US, UK and German side) went away from manual mixture adjustment as you described and were equipped with mixture regulators providing only fixed positions (for example auto-lean, auto-rich, auto-emergency-rich, cut-off, run and various combinations of these).

So, if I use two Saitek throttles quadrants, I’ll have two levers for the throttles, two for the props, one for the mixture, and one for flaps or something else.  Great.  I haven’t flown a twin since the late 70’s, Cessna 310 and 337. Things change.

Thanks,

[No1sonuk]

On 10/2/2021 at 4:18 PM, TWC_SLAG said:

So, if I use two Saitek throttles quadrants, I’ll have two levers for the throttles, two for the props, one for the mixture, and one for flaps or something else.  Great.  I haven’t flown a twin since the late 70’s, Cessna 310 and 337. Things change.

Thanks,

The "something else" could be view zoom.  I have that on the side lever on my Warthog throttle.

[grafspee]

I think mossie lean mixture automaticly when boost is below 7lbs. So mixture lever you touch before start and shut down engine only

[Captain Orso]

There are two plunger/buttons behind the pilot's seat for cutting off the engines. The mixture lever only has Rich and Lean, no cutoff.