Hot Start procedure

[Pat Stewart]

I have a 7A with an YIO360M1B. If this thing runs for just 10 minutes it will require a hot start to get it running. I am interested in what others have done to prevent this issue and or your hot start procedure.

[thinkn9a]

It works for me,...

And there are a few other approaches discussed in the thread

[scrollF4]

I have the exact same engine, and I go all in. The only way I can hot start this engine without backfiring it is by flooding it, and it works every time.

- With throttle wide open and mixture max rich (both levers full forward), I run the boost pump for 6 seconds.

- Keep the throttle wide open, but pull mixture full back to lean cutoff.

- Now, crank the engine. Be mindful of the starter's run time limit, but after about 8-9 seconds the engine will try to catch. It'll spit and fit, but in a few seconds the fuel/air mixture will balance and she'll try to roar to life.

- with both hands, swap the throttle and mixture positions: Pull the throttle back to about 1/2 inch open while advancing the mixture to rich. That takes her back down to normal ops.

- don't forget to turn the alternator on.

This is the only way I ever hot-start my hot engine. I have not had a single backfire since.

[PilotjohnS]

Please do a search. There was a very long and thorough discusion here about this with some really good techniques. I personally wouldnt intentional flood an engine. JMHO

[Schooner69]

Charlie: I'm still having trouble with my hot starts... I'll try yours.

This for anyone: based on the assumption that the only stupid question is an unasked question...

If you've shut down the engine using the mixture control, what is the source of the fuel if you use the hot start procedure...?

J

[Pat Stewart]

This is the way I have always done it but I only run the fuel pump for about 3 seconds, last night it backfired while starting with a nice puff of smoke so of course I kept cranking till it started. Did not like this experience which is why I started this thread.

Originally Posted by scrollF4

I have the exact same engine, and I go all in. The only way I can hot start this engine without backfiring it is by flooding it, and it works every time.

- With throttle wide open and mixture max rich (both levers full forward), I run the boost pump for 6 seconds.

- Keep the throttle wide open, but pull mixture full back to lean cutoff.

- Now, crank the engine. Be mindful of the starter's run time limit, but after about 8-9 seconds the engine will try to catch. It'll spit and fit, but in a few seconds the fuel/air mixture will balance and she'll try to roar to life.

- with both hands, swap the throttle and mixture positions: Pull the throttle back to about 1/2 inch open while advancing the mixture to rich. That takes her back down to normal ops.

- don't forget to turn the alternator on.

This is the only way I ever hot-start my hot engine. I have not had a single backfire since.

[scrollF4]

Well good luck. You'll find a technique that works.

[mahlon_r]

These procedures have worked for me, for many many IO-360 starts in a variety of installations:
Procedure for a cold engine:
(1) Set propeller governor control in "Full RPM" position (where
applicable).
(2) Turn fuel valve "On".
(3) Open throttle wide open, move mixture control to "Full Rich"
turn boost pump on, approximately 3 to 5 seconds, turn boost pump off,
then return throttle to "Closed" and return mixture control to
"Idle Cut-Off".
(4) Open throttle 1/4 to 1/2 of travel. Keep you hand on the throttle during the staring process to make movement toward the idle position after the engine has started an easy immediate thing to be able to do.
(4) Set magneto selector switch (consult airframe manufacturer's
handbook for correct position).
(5) Engage starter.
(6) Engine starts.
(7) Retard throttle towards idle position.
(8) Move mixture control slowly and smoothly to "Full Rich".
(9) Check oil pressure gage. If minimum oil pressure is not indicated
within thirty seconds, stop engine and determine trouble.


Procedure for a hot engine that was shut down with in a few minutes ago:
(1) Set propeller governor control in "Full RPM" position (where
applicable).
(2) Turn fuel valve "On".
(3) Open throttle wide open, move mixture control to "Full Rich"
return throttle to "Closed" and return mixture control to
"Idle Cut-Off".
(4) Open throttle 1/4 to 1/2 of travel. Keep you hand on the throttle during the staring process to make movement toward the idle position after the engine has started an easy immediate thing to be able to do.
(4) Set magneto selector switch (consult airframe manufacturer's
handbook for correct position).
(5) Engage starter.
(6) Engine starts.
(7) Retard throttle towards idle position.
(8) Move mixture control slowly and smoothly to "Full Rich".
(9) Check oil pressure gage. If minimum oil pressure is not indicated
within thirty seconds, stop engine and determine trouble.

Procedure for a hot engine that was shut down more than a couple of minutes ago:
(1) Set propeller governor control in "Full RPM" position (where
applicable).
(2) Turn fuel valve "On".
(3) Open throttle wide open, move mixture control to "Full Rich"
turn boost pump on, approximately 1 second or less, turn boost pump off,
then return throttle to "Closed" and return mixture control to
"Idle Cut-Off".
(4) Open throttle 1/4 to 1/2 of travel. Keep you hand on the throttle during the staring process to make movement toward the idle position after the engine has started an easy immediate thing to be able to do.
(4) Set magneto selector switch (consult airframe manufacturer's
handbook for correct position).
(5) Engage starter.
(6) Engine starts.
(7) Retard throttle towards idle position.
(8) Move mixture control slowly and smoothly to "Full Rich".
(9) Check oil pressure gage. If minimum oil pressure is not indicated
within thirty seconds, stop engine and determine trouble.

[lr172]

Throttle at 1000 RPM setting. Mixture ICO. Crank until it begins firing (~ 4-5 seconds) and then mixture rich. It almost never fully catches, but the next press of the start button and it starts in two blades. I never force it on the first attempt. If it doesn't catch, I stop cranking and wait 10 seconds. I am more patient on the second attempt. During those ten minutes the fuel boils out of the small line above your cylinder and this pushes that fuel into the intake chamber leaving an overly rich mixture that won't combust. It must be purged some how. The reason that it doesn't "catch" and start running after it begins combusintg is that the lines are still empty and it takes a couple of cycles for the fuel to get to the cylinder once you go rich on the red knob.

I don't like starting by using throttle for a variety of reasons and only use throttle to start if I have inadvertently flooded the engine. The above method works every time for me.

Larry

[BillL]

Originally Posted by Schooner69

If you've shut down the engine using the mixture control, what is the source of the fuel if you use the hot start procedure...?

J

The volume of fuel beyond the distribution unit is open to the intake manifold though the injector. It will boil and discharge via the injectors. Not sure what pressure resistance the spider adds, but it also may spill some of its fuel due to expansion.

Refilling this volume is what the 1 sec (or less) boost pump on-time is for.