COME KINDLY TO TERMS WITH YOUR ASS

“Come kindly to terms with your ass, for it bears you.”

  This saying of unknown origin was the first sentence of one of the twentieth century’s most read non-fiction book, and is well applies to the issue of splines. On some CO2 models, the most forward part of the crankshaft is splined, which means grooves are machined into the shaft to positively index the aft propeller disc to the shaft. When properly torqued, the prop is secured to the shaft and may rotate as the crank rotates.

  I know what you’re thinking, “yeah yeah yeah we know that elementary stuff.”

The reason I bring this up, is next to the connecting rod, this is weakest point in many CO2 motors, and should be treated with much respect. Many new-to-CO2 fliers take that aft plate as just another washer, and strip those splines clean off by putting some pliers on that plate and twisting. Now it’s just another washer!

  Let’s say you just bought a Motor off the EBay, and like a lot of them, they are all gummed up and the crankshaft/prop won’t turn. It’s going to take a lot of oil and some back and forth to work that crank loose to be decently rotational. Listen up ~ 

ONLY WORK THE MOTOR BACK AND FORTH WITH A PROPELLER FIRMLY SCREWED INTO THE SHAFT

  If you neglect to do this and the prop is loose, the splines can strip out and you have lost the engine. If at the time you don’t have a suitable prop, use a piece of hardwood or a paintbrush handle, just make certain that backing plate cannot wobble on the shaft end. That aft plate was pressed onto those splines and was not designed to be pulled on and off repeatedly. While we’re on the subject, if you’re trying to loosen a bound-up crank, oil and time works better than force. Be patient, ya hear? 

Oils like 3-in-1 and Kroil are dandy to loosen stuck or seized motors, but after they are loosened and are rotating normally, that same oil must be removed or flushed thoroughly from your crankcase before CO2 runs are accomplished as you don’t want it distributed throughout your plumbing and tank. Verily, verily I say unto you ~

WHAT MAKES THEM OILS GREAT AT LOOSENING STUCK METAL PARTS IS ALSO WHAT MAKES THEM GREAT FOR EATING RUBBER SEALS AND CRAZING NYLON SEATS.

Before using a solvent penetrating oil, take the time to remove and bag the seals and seats so they don’t get any of these reactive oils on them.  Only use a fine mineral oil such as sewing oil, or some Gasparin CO2 motor oil for normal engine operations and after-run. If you’ve never disassembled a CO2 motor, check the tips sheets I have available here at the annex.

Be like Billy . . . Behave yourself!