IO 550 Hot Start

[Don Scorese]

i am trying to figure out the best Hot Start procedure for an IO 550 N. For cold starts I have two procedures and both seem to work well. I am leaning towards using the procedure written in an article by Mike Busch....mixture in, throttle cracked, low boost pump amd crank.

Hot starts I am not as confident I am using the best procedure. The one that seems to work best is.....mixture in, throttle in, high boost pump for 3 seconds, throttle slightly more than cracked, then crank....when it pops use low boost pump. This procedure works most of the time but it doesn't start as quickly as the cold start procedure.

I am curious what procedure works best for others with the IO 550.

And while I'm asking questions......is it normal for the trim wheel in an Ovation to feel much stiffer than a J model?

Thanks,

Don

[KSMooniac]

I believe the continental fuel system returns excess fuel to the tank and the easiest method is to run low boost with the throttle closed for 90 seconds to pump all of the hot fuel and vapor back to the tank and replace it with cool fuel. Then do a cold start.

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[carusoam]

Don,

The fuel system is different for the Continental.

Become familiar with the fuel return line to the selector valve.

This allows fuel to return to the selected tank.

The mixture pulled out, pump on, cool fuel circulates...

Follow the POH, it includes this explanation...just not as specific as I just did...

I am a PP, not a mechanic...

For a regular start the IO550 asks for the throttle to be in while priming... If the throttle is not in, the priming will not be the same.

I'm still not a mechanic....

Best regards,

-a-

[Txbyker]

Quick hands...

Mixture out

Full throttle

High boost 5 count...then quickly

Mixture full

Throttle out and two twist

Start

This procedure usually fires immediately for me.

Russ

[Guest]

Running the airframe boost pump with the throttle closed and the mixture in Idle cut off will recirculate fuel through the engine driven fuel pump and return it to the selected tank. The rest of the fuel system will still contain hot fuel as well as vaporized fuel in the fuel injector, the fuel hoses, the fuel flow transducer and the fuel flow divider. These must ultimately be filled with cool fuel before the engine will run well.

Fuel system set up per SID97-3 and the Mooney maintenance manual are important.

Clarence

[cbarry]

This sequence works well for me: Throttle to idle, mixture to cutoff, run low fuel boost for at least 45 seconds, boost off, throttle full open, mixture full rich, low fuel boost 2-3 seconds, fuel boost off, throttle back to 1/4 open, mixture to cutoff, crank while advancing mixture, throttle back to idle upon start.

[Cruiser]

As described by the Continental Motors reps at a seminar,

 

Throttle - cracked slightly

Mixture - full rich

Crank - should fire in two or three revolutions.

Add Low Boost if engine starts to falter (almost always does so be ready)

Turn Low Boost off, lean for idle.

 

works every time.

[Jeff_S]

Yeah, I agree with Cruiser. I was overthinking hot starts when I first got my Ovation, but now it's very simple. Mixture rich, throttle full, low boost for one or two seconds, then pull throttle to idle and give it two turns, fire away. Be ready with a jolt of low boost if needed if it starts to falter. Only one time did I use the full "clearing" procedure as described above, which does work, but I would only use now as a last resort.

[kmyfm20s]

I do it per my POH and works perfect. Throttle set to idle, mxture rich, low boost pump on. After it starts, lean aggressively and boost pump off. Much easier than my previous J.