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Kickback

FireMedic_2009

Well Known Member
Today I started my plane and just before it started I released the starter too soon and the engine almost started but then the prop turned in the opposite direction for 2-3 rotations but didn’t start. Is the only problem with kickback the starter gear pin can shear on a kickback or are there other problems that can happen?
Thanks
 
Some have reported loosing a tooth or two from the ring gear around the flywheel.
Check that you are only starting on a properly retarded mag. This type of kickback usually happens when an unretarded mag or electronic ignition is "hot" on start up.
 
Today I started my plane and just before it started I released the starter too soon and the engine almost started but then the prop turned in the opposite direction for 2-3 rotations but didn’t start. Is the only problem with kickback the starter gear pin can shear on a kickback or are there other problems that can happen?
Thanks

The early SkyTec lightweight starters could have the nose of the starter broken during a kickback. That weak point was fixed on later models of that starter.
 
And make darn sure you don't re-engage the starter like someone I know (all thumbs). Otherwise, you'll get to amaze your friends with the super simple process of replacing a ring gear with broken teeth.
 
I have a new skytech starter as of 15 months ago. I have an SDS CPi2 dual electronic ignition. It’s never happened before. I just let off on the starter before the engine started. The ignition on both are ON/hot. I am not aware of keeping one mag off during startup and I’ve read the manual several times.
 
Assuming you are using a standard key operated rotary mag switch?
I'm thinkin' that as soon as you relaxed on the key to stop the starter, you then had both mags online, and one of them would not be retarded, hence the possible kick-back.
 
Kick back

Or in my case the shorting link was missing on the keyswitch
It had been like that for years before I brought the aircraft.


Just my 2p worth

Rob
 
If it was just the typical reversal sometimes seen when the engine gets close to starting (weak power pulses from poor mixture), but doesn't there should be no side effects. That would not be classified as a kickback, as the reversal occurs AFTER releasing the starter. If it was an actual kickback, where a normal power pulse occurs too early in the cycle (e.g. too much starting advance) and pushes back against the starter, you likely have cracked teeth on the ring gear.
 
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And make darn sure you don't re-engage the starter like someone I know (all thumbs). Otherwise, you'll get to amaze your friends with the super simple process of replacing a ring gear with broken teeth.

Yep.. first you pull the pan of roasted veg out of the oven... then your new ring gear. Your pilot dinner guests get very amused.
 
I had the same issue with a CPI2 on a IO-360 A3B6D. It blew out the aircleaner twice. Ross or Barry from racetech provided different settings for ´Crank retard´ and ´RPM Ignition 500´. No issues since.
 
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Low battery voltage is a bad thing with any EI as coil triggering is predictive- not like a standard mag. The ECU waits for one complete crank revolution to establish the time period between magnets before initiating the first spark.

Ditto on letting go of the starter switch and then re-engaging before the crank stops turning.

Cranking retard on the CPI-2 is defaulted to 15 deg below about 300 rpm.

Default timing at 500 rpm (lowest programmable range and the one used for cranking) is usually 10 deg BTDC.

This ideally results in the spark firing at around 5 ATDC. (10 minus 15= -5)

You may increase the cranking retard in that window to 20 deg and/or reduce 500 RPM timing to 5 deg. This will fire the spark even later, well after TDC.
 
SureFly voltage

It is preferred to start on the SureFly ignition.
The battery should be able to supply minimum of 8,5 V.
If you have an engine that is stamped 25 deg timing, set ignition to fire 5 deg
after TDC. (not TDC). Set the dip switches to 30 deg timing advance.
This will result in safe start and 25 deg timing above 300 rpm.
If using a key starter switch, be sure that the non starting mag / ignition is
grounded during start. This is regardless using a magneto or two SureFly.

Good luck
 
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