Kickback

[redhawk]

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
stonemtn737@aol.com

[rvbuilder2002]

Originally Posted by redhawk

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
stonemtn737@aol.com

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.

[N131RV]

Originally Posted by redhawk

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
stonemtn737@aol.com

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

[ReadyRV]

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.

[170 driver]

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.

[jetjok]

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.

[dougknight]

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

[Steve Sampson]

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?

[celstar]

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?

[Geico266]

Originally Posted by jetjok

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.

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?