A Kinner gave a friend of mine eight black-and-blue fingers. It took a year for all of his fingernails to grow back. He was lucky. I know of others that have been hurt.
There is only one safe, fool-proof way to hand-prop a Kinner. Using this method, a low compression, cold Kinner will start 10 out of 10 times on the very first pull and you'll come away with all your body parts intact.
First off, it’s important to know that only the top three Kinner cylinders (1, 2 & 5) are plumbed for priming. Secondly, prop indexing on a 5 cylinder Kinner can be confusing to the uninitiated; knowing where blade 1 and 2 are in relation to each cylinder’s power cycle is important. Neither primed cylinder #2 or primed cylinder # 5 will provide a safe, convenient propping position. That leaves primed cylinder #1 (at the 12 o’clock location).
The firing order is 1-3-5-2-4; visualize a star pattern.
With the usual safe propping procedures in place:
1) Clear the lower cylinders of any oil, then set prop blade #2 at the 7-8 o’clock position so that prop blade #1 is set to fire cylinder #1. The Apollo impulse will be in pre-position for the wind-up and snap. Do not disturb this prop position.
2) With the piston now positioned near the top of cylinder #1 (valves closed), enter a sufficient fuel charge into this constricted space with 4-5 primer strokes. Long-stroke, 5 inch bore Kinners like a good shot of fuel to get them going. A partial charge will cause a strong kick-back.
3) With the left mag on (and all your body parts safely outside the prop arc), all that’s needed is a steady horizontal pull with your left hand on blade #2. The Apollo will do its thing, cylinder #1 will literally go off like a shotgun blast and you will be calmly walking toward the left wing.
The Kinner is an outlier. Propping blade #2 from the classic 10 o’clock position with two hands on the prop while standing in or near the prop arc is what causes most Kinner propping accidents. The hair-trigger Apollo and primed cylinder #5 are just waiting to nail you. Oh, and primed cylinder #2 is next in the firing order, so it’s bam-bam got your hand(s).
The long prop on a Kinner swings 144° between each power stroke. Each blade covers a lot of real estate in a blink of the eye. Kinners have a well deserved reputation for hurting hand-proppers. Older Kinner operators would say it’s not a matter of if, but when.
Hope this will help keep someone out there from getting hurt. Stay safe.
Best,
HT & V