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starter kickback on new Surefly installation

roadrunner20

Well Known Member
Need some suggestions on resolving my issue.

On keyed ignition startup... prop will begin start on prop rotation, then reverses slightly, starter re-engages with the grind. Stop
This happens on cold primed start about every second or third start

Here's my setup
left mag: replaced with Surefly, advance 25* timing set on dip switch, set on TDC
right mag; Slick impulse set on 25* BTC

Timing set on starter dot marking.
Engine Superior IO-360

Surefly suggested I look at the voltage at starter to insure > 10V
My starter voltage is 12.8/12.9 volts.

FWIW, I've checked & rechecked timing to above.
 
Are you pulling the mixture back out to start then feeding it in as needed but very slowly?

I’m asking because that kickback is what will happen with PMags if there is excessive leftover fuel in the cylinders on a failed start. The PMag continues to ignite both top and bottom plugs as the prop kicks back and if there is fuel it will try to keep going.

Feeding the mixture very slowly as it starts will resolve the condition I’m describing in the case of PMags.

You may be over-priming a bit as well, prime until you have positive fuel pressure vs a number of seconds.

Also, try 1/4 throttle instead of 1/2.
 
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Are you pulling the mixture back out to start then feeding it in as needed but very slowly?
Mixture out on start. Moderate push to full on start. Most times, I'll get the kickback on just 1/2 prop turn

I’m asking because that kickback is what will happen with PMags if there is excessive leftover fuel in the cylinders on a failed start. The PMag continues to ignite both top and bottom plugs as the prop kicks back and if there is fuel it will try to keep going.
That makes sense.

Feeding the mixture very slowly as it starts will resolve the condition I’m describing in the case of PMags.

You may be over-priming a bit as well, prime until you have positive fuel pressure vs a number of seconds.
Thanks. I'm going to the airport now & will give that a try.

Otherwise, once running, it's very smooth & CHTs very stable
 
Also, try 1/4 throttle instead of 1/2.

Surefly and PMag both have standard recommended start procedures but you may need to tweak a bit.
 
Also, try 1/4 throttle instead of 1/2.

Surefly and PMag both have standard recommended start procedures but you may need to tweak a bit.

Thank you Bill.
Looks like this has resolved the issue. I hope.
Apparently, you were correct in that I was way over primed.

I did 4 starts, following various down times and have had no kickbacks.:)

As you suggested, on my initial start:
1/4 throttle, prime until pressure. Stop.
On starting:
1/4 throttle, from idle cutoff, slowly enrich on engine start

FWIW, I've not been able to locate Surefly's start procedures in my paperwork or their website. Send me a url if you happen upon one.
 
Another thing to consider is what prop you have. If you have a light weight prop, it might not have enough flywheel effect to carry it through the compression stroke. The newer versions of the Pmag software automatically retards the spark to 4* after top center when the start timing is set to TDC. This should prevent kick back. It sounds like you are fuel injected. If that?s the case, you shouldn?t need any prime at all to start the engine if it has been run in the last 2 hours or so. There?s plenty of fuel in the spider to get the the engine started. Leave the mixture in idle cutoff, crack the throttle, and hit the starter. When it fires, slowly bring the mixture out of idle cutoff. No boost pump needed. EI systems start the engine much leaner than mags. You can ?fool? the Surefly into starting at a few degrees after TDC and it shouldn?t affect the ?run? timing. After I installed two Pmags on my previous (RV8) airplane, we had two kick backs with a lightweight Whirlwind prop. The second one broke a few teeth off my starter ring gear. I reset the timing to an extra 2* after TDC. It started fine and I never had another kickback event.
 
you shouldn?t need any prime at all to start the engine if it has been run in the last 2 hours or so

Good point. On "hot" starts I don't prime at all. I just put my throttle at 1/4, mixture closed, start it and slowly feed in mixture.
 
Another thing to consider is what prop you have. If you have a light weight prop, it might not have enough flywheel effect to carry it through the compression stroke. The newer versions of the Pmag software automatically retards the spark to 4* after top center when the start timing is set to TDC. This should prevent kick back. It sounds like you are fuel injected. If that?s the case, you shouldn?t need any prime at all to start the engine if it has been run in the last 2 hours or so. There?s plenty of fuel in the spider to get the the engine started. Leave the mixture in idle cutoff, crack the throttle, and hit the starter. When it fires, slowly bring the mixture out of idle cutoff. No boost pump needed. EI systems start the engine much leaner than mags. You can ?fool? the Surefly into starting at a few degrees after TDC and it shouldn?t affect the ?run? timing. After I installed two Pmags on my previous (RV8) airplane, we had two kick backs with a lightweight Whirlwind prop. The second one broke a few teeth off my starter ring gear. I reset the timing to an extra 2* after TDC. It started fine and I never had another kickback event.

Thank you Scott. Very Interesting.
I do only prime on cold starts.
And yes, I do have a light prop. A Catto 3-blade, 2006 model with no nickel leading edge.
I'll see how it goes & will consider the 2*.
I was beginning to be frustrated with the whole setup & considered going back with my Slick. This at least puts me on a path to some sort of resolution.
 
Update:
I have continued to get kickbacks with the light priming suggestions.
Is it due to my light prop? Need to retard timing?

I'm not interested in testing the retard timing option.
Before I do any damage to my starter, I've decided to go back to my dual slick mags. I've had 13 years of no kickbacks & a reliable starting system.

Thanks you for your suggestions.
 
I also have a light wood prop and had the same issue. My start procedure is:

1) ensure ignition, mixture and fuel is off

2) rotate the prop slowly and let the pressure bleed off from the compression stroke.

3) start the plane as normal.

Getting the compression out seems to help drastically with kick back. It always seems like the first rotation is where I had issues from not having enough momentum to swing the prop, resulting in kick back. I started doing this after I broke a starter from the same issue. Since I've started doing this I haven't had any kick back.

Be super careful when doing this, you don't want to accidently hand prop it!
 
I also have a light wood prop and had the same issue.
Getting the compression out seems to help drastically with kick back. It always seems like the first rotation is where I had issues from not having enough momentum to swing the prop, resulting in kick back. I started doing this after I broke a starter from the same issue. Since I've started doing this I haven't had any kick back.

Yes. My kickbacks were always on the first rotation too.
 
We get comments pretty frequently about kickbacks with a couple of popular EI brands. Assuming you have the EI set as per manufacturer's instructions, a good battery and starter to swing the prop smartly, the cause is simply not enough retard during cranking. This is really a software issue which in itself, shows a lack of testing before product release.

A marginal battery or starter can cause overly advanced ignition timing while cranking as the crank slows locally as it comes up on compression.
 
.....

Surefly suggested I look at the voltage at starter to insure > 10V
My starter voltage is 12.8/12.9 volts.


FWIW, I've checked & rechecked timing to above.

The most likely issue is a lack of proper retard during starting; however, 12.8/12.9 volts at the starter seems unusually good. Is that the voltage UNDER LOAD during the start?
 
10V under starter load is a good number so that is not the issue. The only way you can get kickbacks is if ignition happens too far BTDC.
 
The most likely issue is a lack of proper retard during starting; however, 12.8/12.9 volts at the starter seems unusually good. Is that the voltage UNDER LOAD during the start?

No. This was not under load. Since I?ve never experienced a load issue, I didn?t pursue it further. Not a tired battery either as it was replaced 6 months old.

Thank you all for your input.
 
Does the surefly have a method to alter the start retard timing during configuration setup? The SDS products are user configurable and mine is set to fire 3 degrees AFTER top dead center any time the starter is engaged. This means there is no way to get a kick back no matter the prime, start technique, weight of the prop, etc. I know some other ignition products have a start retard functions as well, but it's only engaged on the first revolution of the prop. If it doesn't catch the first time, you need to cycle the ignition off and on to reset the retard. Is the surefly like this?
 
No. This was not under load. Since I?ve never experienced a load issue, I didn?t pursue it further. Not a tired battery either as it was replaced 6 months old.

Thank you all for your input.

Battery condition does not ensure that the starter is seeing the proper voltage. Need to test this under load. Easy to do and could very well be your issue.
 
Does the surefly have a method to alter the start retard timing during configuration setup? The SDS products are user configurable and mine is set to fire 3 degrees AFTER top dead center any time the starter is engaged. This means there is no way to get a kick back no matter the prime, start technique, weight of the prop, etc. I know some other ignition products have a start retard functions as well, but it's only engaged on the first revolution of the prop. If it doesn't catch the first time, you need to cycle the ignition off and on to reset the retard. Is the surefly like this?

No option to retard timing.
 
Random thoughts
Can you disable one ignition at a time & try to see which is causing the issue? Would insure that your adjustments are being applied to the culprit. If you are using 2 switches, would be an easy test.

Do you use a conventional dual mag ignition switch? Did you remove the jumper that disables the RIGHT mag position during start? Ideally it would be best timing wise to start on one ignition, you choose.
If you are using the dual mag switch, the old mag configuration was to disable the Right (non-impulse) mag and start on the Left impulse one only. But you?re current installation has the impulse mag in the Right hole.

Good luck in your trouble shooting
 
For those of you with light weight props and start systems involving two toggles type switches and a push button starter - try spinning the engine with the starter with the toggles (ignition switches) off for about 4 blades, then turn on one or both ignition switches. The prop will have developed enough momentum at that point to carry the engine/prop through the compression stroke and shouldn’t kick back. If it does, you have a timing problem. EMagAir has a system called ‘Run Mode Start Delay (RMSD) that can be programmed and does essentially this same thing automatically. You can do the same thing manually using the start principle I’ve described above, and it should work on any EI system if the ignition is individually switch controlled. You could also just set your start timing at 5 degrees after top dead center instead of TDC. This will affect you max advance on a Pmag by 5 degrees, and maybe others as well, but it will cure a starter kick back. But manually delaying ignition until the engine is spinning works too. That’s what we did on the big recips back in the day, but for a different reason.
Kick backs are typically more likely on a hot start or on an over primed engine, so maybe you wouldn’t have to do it always. I’m pretty sure it would always start this way, even if cold if you’ve given it some prime. Can’t hurt to try.
 
...or you could just buy an ignition that does what you program it to do in the first place.

It's incredible that in this day and age, 50+ years after EI appeared in cars, we still have to mechanically spoof an aviation EI to behave. Thankfully, they don't all do this.
 
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I’m asking because that kickback is what will happen with PMags if there is excessive leftover fuel in the cylinders on a failed start. The PMag continues to ignite both top and bottom plugs as the prop kicks back and if there is fuel it will try to keep going.

Although fuel plays a role in what happens after the plugs fire, it has no effect on when the plugs fire.

Here the fundamental concern is when. In general, firing at TDC or a little before is fine given lots of prop inertia, while a low mass prop requires start timing no earlier than TDC, with a few degrees after TDC being desirable.

I'm not interested in testing the retard timing option. Before I do any damage to my starter, I've decided to go back to my dual slick mags.

I am surprised, as the Surefly should be really easy to clock at installation. The website says start timing is 0 below 400 RPM, and the DIP switch settings allow selection of 25, 26, 28, or 30 BTDC, fixed or variable. So, for example, if the owner wishes the plugs to fire at 3 degrees after TDC, simply set the DIP switches for 28 and do the initial timing at 3 ATDC. Or set 30 and do the initial at 5 ATDC.
 
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Although fuel plays a role in what happens after the plugs fire, it has no effect on when the plugs fire.

Here the fundamental concern is when. In general, firing at TDC or a little before is fine given lots of prop inertia, while a low mass prop requires start timing no earlier than TDC, with a few degrees after TDC being desirable.



I am surprised, as the Surefly should be really easy to clock at installation. The website says start timing is 0 below 400 RPM, and the DIP switch settings allow selection of 25, 26, 28, or 30 BTDC, fixed or variable. So, for example, if the owner wishes the plugs to fire at 3 degrees after TDC, simply set the DIP switches for 28 and do the initial timing at 3 ATDC. Or set 30 and do the initial at 5 ATDC.

Dan
Could you hum a few more bars about the setup as I was also thinking of putting a SureFly on this winter and also have a Catto prop (0-360), but like Dan my two Slick mags have worked fine for 11 years with no kickbacks and I do not want to create a starter problem. I also have the regular key switch start so was thinking of replacing the impulse mag on the left.
Figs
 
Dan
Could you hum a few more bars about the setup as I was also thinking of putting a SureFly on this winter and also have a Catto prop (0-360)...

For you Figs....anything ;)

The engine side of a standard Lycoming flywheel looks like this:

Timing%20References.jpg


When installing a Surefly the standard way, the timing reference is the hash mark at "TC | #1". You would begin the installation by setting the crank position so that hash mark is aligned with the crankcase split line. When installed in this standard fashion, below 400 RPM the Surefly should fire when the zero hash mark is aligned with the case split, and then advance the firing point with increasing RPM.

To clock the system so it fires after TDC below 400 RPM, you'll create a new mark on the flywheel. If you have the usual 141 tooth ring gear, the simple approach to a 5 degree offset is to make a new mark 2 teeth to the left of the zero hash mark (360/141=2.5 degrees per tooth). Or you could measure the gap between the 20 and 25 degree marks, and use the dimension as a 5 degree gauge. Either way, the new 5 degree ATDC mark will be close to the stem of the "T" in "TC".

In a standard installation for a parallel valve 360, you would set the DIP switches for 25 degrees, either fixed or variable. In our new clocked setup, set them for 30 degrees, fixed or variable. Now do the actual installation per the instructions, with only one change...align the case split with the new reference line, rather than the factory TC hash.

The result will fire 5 degrees after TDC while cranking, then advance to 25 before TDC at full throttle
 
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For you Figs....anything ;)

The engine side of a standard Lycoming flywheel looks like this:

Timing%20References.jpg


When installing a Surefly the standard way, the timing reference is the hash mark at "TC | #1". You would begin the installation by setting the crank position so that hash mark is aligned with the crankcase split line. When installed in this standard fashion, below 400 RPM the Surefly should fire when the zero hash mark is aligned with the case split, and then advance the firing point with increasing RPM.

To clock the system so it fires after TDC below 400 RPM, you'll create a new mark on the flywheel. If you have the usual 141 tooth ring gear, the simple approach to a 5 degree offset is to make a new mark 2 teeth to the left of the zero hash mark (360/141=2.5 degrees per tooth). Or you could measure the gap between the 20 and 25 degree marks, and use the dimension as a 5 degree gauge. Either way, the new 5 degree ATDC mark will probably be very close to (if not on) the stem of the "T" in "TC".

In a standard installation for a parallel valve 360, you would set the DIP switches for 25 degrees, either fixed or variable. In our new clocked setup, set them for 30 degrees, fixed or variable. Now do the actual installation per the instructions, with only one change...align the case split with the new reference line, rather than the factory TC hash.

The result will fire 5 degrees after TDC while cranking, then advance to 25 before TDC at full throttle

DanH & figs, I'll send you a PM as I don't feel comfortable posting it to the forum. I'll only say this, I should have just entrusted VAFers to assist in troubleshooting. I'd probably be flying with it today.
 
I do not know anything about the Surefly igntion but do know a thing or two about P-mags.

... After I installed two Pmags on my previous (RV8) airplane, we had two kick backs with a lightweight Whirlwind prop. The second one broke a few teeth off my starter ring gear. I reset the timing to an extra 2* after TDC. It started fine and I never had another kickback event.

Try starting your engine on one igntion and then the other. Whichever one is kicking back is the one you need to address.

If your P-mag is version 40 or higher, it will fire the ignitions at a little over 4 degrees after TDC when below 400 RPM's. Prior to firmware version 40, they fired at TDC and were prone to kickbacks, if the battery was weak or they weren't set to exactly TDC. Version 40 came out around four years ago, +/-. (I don't remember the year.)

It is unlikely that you will get a kickback from the P-mags, if they are up to date.

I have been running a two bladed Catto (Can't get much lighter) and have never experienced a kickback.

However, if you are "clocking" the P-mag and go the wrong way, you could introduce a kickback.

Basically, what I'm saying is, figure out which igntion is causing the issue and contact them.
 
If your P-mag is version 40 or higher, it will fire the ignitions at a little over 4 degrees after TDC when below 400 RPM's. Prior to firmware version 40, they fired at TDC and were prone to kickbacks, if the battery was weak or they weren't set to exactly TDC. Version 40 came out around four years ago

Possibly a lesson Surefly is learning (Caution; speculation).

The EDIS modules I'm flying fire the plugs something before TDC at cranking speeds. The degree value of "something" appears to vary with Motorcraft ignition module part number; various sources report different values. It has not a been an issue for me, as I'm spinning a metal BA Hartzell; mass moment of inertia is high.

However, just for field experience, I ran an EDIS clocked 10 degrees for almost a year, meaning ignition when cranking was well after TDC. With the heavy Hartzell, it is the smoothest, most turbine like start you can imagine. If I were marketing an ignition system with fixed parameters (warning, opinion), they would all go out the door with timing below 400~500 RPM set at 5 ATDC. It would accommodate low mass props, and the high mass crowd will like it too. And "clocking" would not be required.

E-Mag made a good call.
 
Agree with Dan. The safest bet is to fire ATDC. Digital EI timing accuracy during cranking may not be so accurate depending on prop inertia, sensor sampling rate, software and how the battery/starter cranks the engine over.

Firing BTDC is tempting fate that something will go wrong and you may break a starter. I've received at least 10 reports now on other EIs kicking back on starting and breaking starters. One guy broke 3 starters until he ditched that brand.
 
With the regular keyswitch setup I assume that if I put the SureFly on the right and left the impulse mag on the left then the SureFly would be disabled during start and the motor would start on the mag (normally one or two blades). This would mean the standard SureFly setup would be fine. Is this correct?
Figs
 
With the regular keyswitch setup I assume that if I put the SureFly on the right and left the impulse mag on the left then the SureFly would be disabled during start and the motor would start on the mag (normally one or two blades). This would mean the standard SureFly setup would be fine. Is this correct?
Figs

Yes, that's right, you would still be starting on the impulse mag. This has the benefit of keeping the start timing the same that you have had before. If it has worked well, it will continue to work well. You don't hear about kickbacks too often with impulse mags.

The down-side of that approach is that you are still getting only the weaker spark of the impulse mag to start on, rather than a nice strong EI spark.

This is the dilemma that everyone thinks through and makes a choice.
 
With the regular keyswitch setup I assume that if I put the SureFly on the right and left the impulse mag on the left then the SureFly would be disabled during start and the motor would start on the mag (normally one or two blades). This would mean the standard SureFly setup would be fine. Is this correct?
Figs

If the SureFly is firing after TDC, and I don't know if it is or is not, then you are better off starting on the electronic igntion.
 
Slick Start option

Yes, that's right, you would still be starting on the impulse mag. This has the benefit of keeping the start timing the same that you have had before. If it has worked well, it will continue to work well. You don't hear about kickbacks too often with impulse mags.

The down-side of that approach is that you are still getting only the weaker spark of the impulse mag to start on, rather than a nice strong EI spark.

This is the dilemma that everyone thinks through and makes a choice.

A SLICK START MODULE WILL BOOST THE IMPULSE SPARK VOLTAGE AS MUCH AS 300% only while the starter is energized. Almost as good as an EI for starting. They work well.
 
Voltage while cranking.

Interesting. Maybe I missed it, but did cranking voltage at the starter get measured? Perhaps humor us and eliminate a resistance problem by measuring voltage at the starter while cranking. Maybe a high resistance termination, a poor ground, or? is contributing to the issue. (A 24 awg wire would give you battery voltage anywhere when there is no load, so measuring voltage without load only tells you if a circuit is open, not how poor it might be under load). Maybe not a factor, but IMO worth checking.
 
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