Aerovee hot starts

[Bryan Cotton]

Hey all,
I've got a couple of hot starts under my belt. Both after flights and at the pump. I find that it tends to quit on me, unless I use both ignitions and a lot more throttle/RPM until it gets happy. Anybody else see this, or have a suggestion?

Thanks!

[gammaxy]

Always shutdown with the fuel valve and pull the mixture lean. This will reduce the amount of fuel that drips into your air filter.

Start with the mixture full lean and go rich once the engine starts to fire. Keep holding the starter until it's really started--it's possible it fires and goes lean before you have a chance to get the mixture all the way in. If it doesn't fire after a couple seconds, keep holding the starter, make sure the ignitions are actually on and go rich. If it's still not firing and you want to give up, I recommend pulling the mixture back lean while continuing to run the starter to minimize the fuel that drips into the filter.

I think the theory of starting with an Aeroinjector is to reduce the amount of fuel that drips into the filter. I never let go of the starter until the engine is started. Never hang out with the mixture full rich and the propeller not spinning. If there's any risk you're "flooded", pull the mixture lean while continuing the turn the starter.

[Area 51%]

To avoid "pooling" of fuel in the air filter, I drilled a #40 drain hole in the aft portion of the plate. Anything smaller than that was welcome to inspect the inner workings of my engine.

[Bryan Cotton]

Thanks guys. I've been shutting down with mixture followed immediately with the fuel shutoff. Not sure if fuel shutoff first would make a big difference but I'll try it.

Typically I crank it fuel on, mixture off. After I get a bunch of blades (the thing spins fast on the starter) I push the mixture in.

It always fires immediately once the mixture is in far enough, but it seems to quit for hot startup unless I give it extra throttle.

[Bryan Cotton]

Good views of my startup and shutdown technique here.

[gammaxy]

Awesome video.

If this was a cold start, I would typically go full rich immediately before engaging the starter. This way my hand's on the throttle and ready to adjust for ~1200 rpm or so. I also hold the starter in for a moment after it starts until I'm confident the engine isn't going to quit immediately, possibly as I adjust the throttle a bit. This probably means I hold the starter in for about a second after the engine actually fires. I think it came pretty close to quitting on you there. As you can tell, it really doesn't run well around 650rpm especially when it's cold. I've adjusted my idle stop closer to 800rpm when warm.

For a hot start, I'd do it like you with my hand on the mixture, but I'd have the throttle pre-set to my muscle-memory ~1200rpm position :-)

I believe shutting down with the fuel cut-off will tend to use up more of the fuel in your hoses so it doesn't drip into your fuel filter after shutdown.

I notice you have several checklist items before you shutdown. I know some people are concerned about damage to electronics, but I'm unaware of any mechanism where that could happen. I typically shut down the engine first and then take care of the electronics. I leave the switch for my EFIS on so it is always on when the Master is on--so far it's prevented me from forgetting to turn the Master off.

[Onex107]

Test your mixture in the shut off position. You may find, like I did, that it still drips fuel. Shutting off the main valve before the mixture relieves the head pressure in the line and lessens the drip. It's possible that over night the line continues to drip and forms an air bubble in the line, which could be the reason for the big burp upon WOT during takeoff. Just sayin.

[Bryan Cotton]

So I did a shutdown with the fuel instead of the mixture. It takes a second or two to die. I like it.