how to bench test my shower of sparks

[N605RV]

Hi everyone,
My RV4/Lyc 0-360 has always started on just a few revolutions, usually on the 1st or 2nd turn and never past 4. Then all of a sudden I have to crank it multiple times. For reasons I won't go into now, I suspect the 20 year old shower of sparks could be the culprit. What is the simplest way to test it?
Can I simply remove the two wires that connect it to the starter circuit, and using a battery charger, add power to the shower of sparks while still mounted on the firewall and listen for the famous 'buzz'? If i hear it, is it definitely functioning?
thanks!
Mike in Boulder
RV605RV

 

[BobTurner]

Hi everyone,
My RV4/Lyc 0-360 has always started on just a few revolutions, usually on the 1st or 2nd turn and never past 4. Then all of a sudden I have to crank it multiple times. For reasons I won't go into now, I suspect the 20 year old shower of sparks could be the culprit. What is the simplest way to test it?
Can I simply remove the two wires that connect it to the starter circuit, and using a battery charger, add power to the shower of sparks while still mounted on the firewall and listen for the famous 'buzz'? If i hear it, is it definitely functioning?
thanks!
Mike in Boulder
RV605RV

Carefully rotate the prop in the normal direction, stop just short of TDC for #1. Pull the #1 plug that is fed by the left mag. Reattach the lead from the mag, lay the plug on the cylinder fins for a ground and where you can see the electrodes. Make absolutely sure you cannot power on the starter, and as above, power on the shower of sparks. Carefully bump the prop toward TDC. When you get there, you should see lots of sparks jumping across the electrodes.

 

[Freemasm]

Mr. Turner beat me to it. SOS is one of the better innovations from way back. While they can go bad, the induction vibrator proper is fairly bullet proof. The 50 year old one in my Mooney was still going strong when I sold it.

Do as Mr. Turner suggests. However if your PP starts and no kickback experienced, the problem may well lie with external device wiring, leads, plugs. The overused “think outside the box” has some relevance here.

Best of luck and keep us informed.

 

[rocketbob]

If i hear it, is it definitely functioning?

No. They can buzz and have low voltage output. Point gap inside needs to be set with feeler gage and spring tension set so the current draw is to spec. Points need to be cleaned up with a file. I set everything up on the bench with an old magneto coil, crude spark gap and a power supply with a ammeter on the output.

 

[BillL]

After your diagnosis . . . .

I might know where one is for sale if interested.

PM or lanewsjr at gee male bla yada.

 

[N605RV]

Shower of Sparks

Hi Bill, I may need one after the test. If so, yes, will let you know (a new one from Aircraft Spruce is $795..!)
Thanks
Mike
720 320 4189