HOT START PROCEDURE

[GeeBee]

I have to say all the machinations seem overly complicated. Usually on my IO-550 G I hot start by putting the mixture rich, don't touch the throttle from where I shut it down with and crank. 9 times out of 10 it catches in 3 blades or less and if the engines starts to dies from sucking a little fuel vapor I hit the low boost for a second or two and it idles right up. This way, there is no excess fuel dumping into stopped cylinders or leaking from the sniffle valve (by the exhaust pipe no less). Very clean, very safe.

For the 1 out of 10 times the above does not work. I set the controls for a normal start. Give a little prime with the low pump and throttle then turn boost off return throttle to idle. Start cranking and and slowly advance the throttle until air and fuel match up and I get a light off. If you get a big rpm burst,  you used to much prime. 

The above methods keep excess fuel from dripping all over the place and fouling your plugs and washing your cylinders. They require only one hand and one control, the throttle. The idea is to start with as little fuel as possible. 

[Schllc]

This tip is great!  
While my previous method of high boost at full rich and throttle, the to fuel cutoff throttle halfway and slowly enrich till start works 90% of the time, it wasn’t as smooth and easy as your method. 

Thanks!!!
 

[kevinw]

On 12/1/2023 at 3:42 PM, GeeBee said:

I have to say all the machinations seem overly complicated. Usually on my IO-550 G I hot start by putting the mixture rich, don't touch the throttle from where I shut it down with and crank. 9 times out of 10 it catches in 3 blades or less and if the engines starts to dies from sucking a little fuel vapor I hit the low boost for a second or two and it idles right up. This way, there is no excess fuel dumping into stopped cylinders or leaking from the sniffle valve (by the exhaust pipe no less). Very clean, very safe.

For the 1 out of 10 times the above does not work. I set the controls for a normal start. Give a little prime with the low pump and throttle then turn boost off return throttle to idle. Start cranking and and slowly advance the throttle until air and fuel match up and I get a light off. If you get a big rpm burst,  you used to much prime. 

The above methods keep excess fuel from dripping all over the place and fouling your plugs and washing your cylinders. They require only one hand and one control, the throttle. The idea is to start with as little fuel as possible. 

I read this on a previous post you commented on and thought I'd give it a try. I have to say, after using this method 3-4 times, it has worked flawlessly. As you mentioned, the key is to be ready for the boost pump when it stumbles. Good advice, thanks.

[exM20K]

On 12/1/2023 at 4:42 PM, GeeBee said:

I have to say all the machinations seem overly complicated. Usually on my IO-550 G I hot start by putting the mixture rich, don't touch the throttle from where I shut it down with and crank. 9 times out of 10 it catches in 3 blades or less and if the engines starts to dies from sucking a little fuel vapor I hit the low boost for a second or two and it idles right up.

This is what Don Maxwell told me to do, and it works shockingly well for me. Just put stuff where it was before you shut dow.

@mike_elliott’s method also works, but I have to text him to send me the recipe when I infrequently need it.

-dan

Edited January 31 by exM20K

[Will.iam]

On 12/1/2023 at 3:42 PM, GeeBee said:

I have to say all the machinations seem overly complicated. Usually on my IO-550 G I hot start by putting the mixture rich, don't touch the throttle from where I shut it down with and crank. 9 times out of 10 it catches in 3 blades or less and if the engines starts to dies from sucking a little fuel vapor I hit the low boost for a second or two and it idles right up. This way, there is no excess fuel dumping into stopped cylinders or leaking from the sniffle valve (by the exhaust pipe no less). Very clean, very safe.

For the 1 out of 10 times the above does not work. I set the controls for a normal start. Give a little prime with the low pump and throttle then turn boost off return throttle to idle. Start cranking and and slowly advance the throttle until air and fuel match up and I get a light off. If you get a big rpm burst,  you used to much prime. 

The above methods keep excess fuel from dripping all over the place and fouling your plugs and washing your cylinders. They require only one hand and one control, the throttle. The idea is to start with as little fuel as possible. 

This is the way. I have a tsio-360mb and this works the best for up to about 45 mins ground sit. After an hour it will need a boost of fuel to start as everything else evaporated away. The theory as it was explained to me was after the divider all those fuel lines above the hot engine start rising in temperature expanding the fuel in the lines. This pushes that fuel out the injectors already priming the engine. When you start in this situation the engine is already rich but will quickly run through that fuel if you just hit the boost pump for a second or two it will expedite pushing through the air that was in the line and get more fuel to the injectors. But at least the engine is running instead of the starter all this time. Before this method i was cranking for 5 to 10 seconds at a time. With the way geebee uses the engine catches in one to two blade swings or 1 to 2 seconds far quicker and way less stress to the starter motor and battery. If you are too slow or engine died before you got to the boost pump, now at least you know you are starting from a lean position. 

[mike_elliott]

41 minutes ago, exM20K said:

This is what Don Maxwell told me to do, and it works shockingly well for me. Just put stuff where it was before you shut dow.

@mike_elliott’s method also works, but I have to text him to send me the recipe when I infrequently need it.

-dan

The Continental heat soaked method I use was from Mikey Miles, who like Don, probably hot started more planes per day than your average mooney pilot. The theory is to over supply with gas by high boost until max fuel flow, then let the air fuel mixture come together by starting with all the money knobs at full spend, then slowly reducing the MP and stopping 1/2 way while cranking until the right air fuel mixture hits. Once caught, you may need to work the MP like a 55 chivvy throttle to keep it alive. It also works fine on just hot starts, but Dons' method is just peachy for that.

[JimMardis]

Learned a lot from reading this thread. Thanks a lot. Us newbies need all the help we can get. No sense in reinventing the wheel.


Sent from my iPhone using Tapatalk

[JimMardis]

https://www.instagram.com/reel/C8aZ2bfv_7N/?igsh=Y3ljZGRsMzNsY2lr


Just when I thought I had it all figured out, I saw this!!!!


Sent from my iPhone using Tapatalk

[dkkim73]

Very timely thread resurrection. 

I have been having a devil of a time with hot starts. Following POH recs and basic info, the only luck I'd had early on was converting hot starts to flooded starts, then using that procedure. I then came across the discussion about recirculating fuel in the upstream lines (that would vaporize)  by running the boost pump at idle cut-off (ICO) and throttle closed. I even read a column by John Deakin saying to run the pump for a full minute. 

None of that really helped. I observed that the fuel flow was definitely above 0 during these attempts. Wondering if something was wrong, I posed the problem to Savvy. 

A senior A&P who knows Mooneys well said that TCM changed the fuel pump design since my plane was built (2009 ish), and that I must have the new design, which lets fuel into the engine during this notionally-dry-and-sterile process (I think this might explain a difference of understandings early in this thread, though the discussion involved multiple things). 

So... the recommendation was to run for a modest time, 10-15 sec, knowing that there would both be cooling and filling of the lines, and some priming/flooding, then starting with Mix FWD and throttle starting at closed but advanced to hunt for the right mix (akin to what Mike Elliot discusses above). I've had one good start that way, though it was about 40 min later, so not hot-hot. 

Still working on it but wanted to share some info that might help move us towards a Grand Unified Hot-Start Theory. 

[Fly Boomer]

On 6/25/2024 at 11:39 PM, dkkim73 said:

Grand Unified Hot-Start Theor

Part of the soon-to-be-published TOE.