redhawk

redhawk

Well Known Member
I just read Steve's post on his starter problems which inspired me to post this...
I frequently (if not every 1st start of the day) will get a pretty severe kickback on initial start up on my Lyc O-360. I have 2 Bendix mags (no EI).
I am new to my RV4 (I bought it built), and am concerned that this is a bad problem to have. I also have a Skytec starter.
Is there something I can do to prevent kickback?

Thanks,
Dick
[email protected]
 
redhawk said:
I just read Steve's post on his starter problems which inspired me to post this...
I frequently (if not every 1st start of the day) will get a pretty severe kickback on initial start up on my Lyc O-360. I have 2 Bendix mags (no EI).
I am new to my RV4 (I bought it built), and am concerned that this is a bad problem to have. I also have a Skytec starter.
Is there something I can do to prevent kickback?

Thanks,
Dick
[email protected]
Click to expand...

Do you have a standard key ign switch?
If so then the first thing to check would be sure you have the ground jumper for the right (non impulse mag) installed on the starter switch.
 
redhawk said:
I just read Steve's post on his starter problems which inspired me to post this...
I frequently (if not every 1st start of the day) will get a pretty severe kickback on initial start up on my Lyc O-360. I have 2 Bendix mags (no EI).
I am new to my RV4 (I bought it built), and am concerned that this is a bad problem to have. I also have a Skytec starter.
Is there something I can do to prevent kickback?

Thanks,
Dick
[email protected]
Click to expand...

I also had kickback problems that ruined my ring gear and one starter on an IO360-A1B6 with bendix mags. I did not have the "one mag is grounded" jumper installed. Apparently Bendix mags will throw a hot spark at relatively low rpm.

Combined with very good compressions (78 and 79/80 on most) this caused my problem. I installed the "ground the non-impulse mag" jumper on my ignition and verified that it worked. It only helped "somewhat".

In my next incarnation, I am going to have mag switches to allow me to spin the engine before engaging the mags. It almost always "kicked" on the first blade if it was going to. Funny thing, mine went a long long time before the first kickback, and then wanted to kick on almost every start after that.

A slow starter or low battery will add to the problem as well, as well as having your timing set too far advanced.

Just my 2 cents.
JP
 
kickback

You can have the ground strap on your ignition switch and still have a problem if the switch is worn or defective. You should check the timing first as this is the leading cause of kickback. You should then check to be sure you don't have a loose or broken P-lead. Wrong magnetos with incorrect lag angle can cause kickback as well as worn out mags.
 
Kelly makes a Edrive starter that is supposedly immune to kickback, I have one on my RV9 0320 and it works good so far but I havn't had a kickback that I know of. Spruce has them, I think mine was around 450.
 
Not Rocket Science

Magnetos and impulse couplings have been around for a long time and are a very simple and trustworthy system. If all components are installed an functioning properly, you should be having no "kickback" problems.
I would check all of the following;

1. Are the mags timed correctly, and is the impulse firing at the proper location (TDC)? Remove all spark plug leads and the top or bottom plugs for your safety first! Bring cylinder #1 to compression and continue to rotate until the impulse snaps. When the impulse snaps, check the mark on the flywheel to assure that it is at 0/TDC. Back the prop up to about 30 degrees and attach your synchronizer box. Check the mag timing on both mags to 25 degrees BTDC.
2. As was previously mentioned, check to assure that the "non-impulsed" mag grounds properly when the switch is selected to "start". You should check the switch, and the P-leads.
3. If the problem persists, pull the wire for the "non-impulsed" mag (likely the right) fromt he switch. Using a jumper wire, ground the mag and start the engine a few times. You should have no kickback at all.

If you are lucky enough to have Bendix mags, do not ever be tempted to replace them with the other brand. A properly set up Bendix mag has a coming in speed of about 75-90 RPM. With the modern starter technology, the engine is definitely spinning fast enough during start to produce a spark without an impulse coupling.

If you continue to have problems, email me personally and I will be happy to help you out.
 
Scott:

I have the standard issue switch # ES A-510-2k from Van's in my 9-A (not sure if the 4 uses the same, drawing OP-10 referes to the 6,7,8,9 only).

Anyway my question is, if somehow the leads got reversed at the switch(dog or the neighbor guy done it) so as the right (non impulse mag) now doesn't have the ground strap option (it is hooked up to the left or impulse mag which doesn't have the option on the switch) could this leave one susceptable to "kickback"? And thus the Starter failure?

Perhaps Steve and I should keep a little closer tabs on the dog or the guy down the street. huh?

Psst Steve...You checked your switch?


doug
 
Doug, I hadnt seen this thread. In my case that is not my problem. To start my aircraft the sequence is this:

1. Turn the master - ON (This puts power on the P-mags among other things.)
2. Turn two more switches (L & R P-mag ) - ON (Now the mags will fire as reqired.)
3. Operate the starter which is a fourth spring loaded switch.

I am a bit puzzled. My understanding from the other thread was that you are running P-mags, but below you are talking about reversing between impulse and non impulse mags?
 
Keeps engaged.

On my 7 it sounds like when the engine fires i hear the starter still engaged with the ring gear for a few seconds then the sound goes away, this does not happen at every start but it does on most. What would cause this?
 
jetjok said:
2. As was previously mentioned, check to assure that the "non-impulsed" mag grounds properly when the switch is selected to "start". You should check the switch, and the P-leads.
Click to expand...

I don't have a key, push button start only, dual Slicks. How can the mag ground out during start in this situation? Should I turn the right mag off for starts?
 
Starting on left mag only

Geico266 said:
I don't have a key, push button start only, dual Slicks. How can the mag ground out during start in this situation? Should I turn the right mag off for starts?
Click to expand...

Hi Larry,

The Z-11 diagram of the AeroElectric Connection has a switch arrangement that only allows starting on the left mag. If the right mag is "hot", the starter is not allowed to engage. I'm sure it could be adapted to a switch and push button arrangement.
 
Mags On, Mags Off

Geico266 said:
I don't have a key, push button start only, dual Slicks. How can the mag ground out during start in this situation? Should I turn the right mag off for starts?
Click to expand...

Larry,
Do you by some chance have impulse couplings on both mags? If not, the non-impulse mag should be off for start. My PA-20 has a mag switch with only OFF/LEFT/RIGHT and a separate start switch, so I must start with on the right mag only. If your start switch is wired as shown by the drawing referenced by David Nelson, then I would say you are covered.
That was a great link, David! Thanks!
 
jetjok said:
Larry,
Do you by some chance have impulse couplings on both mags? If not, the non-impulse mag should be off for start. My PA-20 has a mag switch with only OFF/LEFT/RIGHT and a separate start switch, so I must start with on the right mag only. If your start switch is wired as shown by the drawing referenced by David Nelson, then I would say you are covered.
That was a great link, David! Thanks!
Click to expand...

Thanks Dave & Mark!

I just pulled the EI off and installed dual Slicks, left only is impulse. I'll put it in the POH, and make a label for the panel to only start on the left mag. I'm assuming as soon as it pops over you can flick the right mag on.

Learn something new everyday here.
 
Last edited:
dougknight said:
Scott:


Anyway my question is, if somehow the leads got reversed at the switch(dog or the neighbor guy done it) so as the right (non impulse mag) now doesn't have the ground strap option (it is hooked up to the left or impulse mag which doesn't have the option on the switch) could this leave one susceptable to "kickback"? And thus the Starter failure?


doug
Click to expand...

Yes!

Start locking the tool box so the dog cant get into it.
 
celstar said:
On my 7 it sounds like when the engine fires i hear the starter still engaged with the ring gear for a few seconds then the sound goes away, this does not happen at every start but it does on most. What would cause this?
Click to expand...

This is inherent to the design of the starter drive. Skytec says it has no effect on the starter. If you don't like the noise, you can activate the starter solenoid with a wire from the main starter relay which will help disengage the drive sooner after engine start.
 
**** that Dog!

Thanks scott!


Steve:
Yes, both are slick p mags. Left has an impulse coupling, right is non-impulse.
And yes I agree you probably don't have the same situation sith your set up. You know the continuity of your circuitry. With the all in one switch I have I do not know its internal wiring and how switching effects its internal continuity(it did not have a diagram).

At this point I am not sure the leads are reversed, won't know untill I get some time on Sunday to trace them out. If they are the Dog is going on Biscut Rations.
 
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