On Saturday, July 26, 2008 at 12:32:22 PM UTC-4, terry wrote:
On Jul 26, 1:56 pm, KLS <[email protected]> wrote:
On Sat, 26 Jul 2008 06:53:18 -0700, Kevin Ricks <[email protected]> wrote:
This is how I start a motor, maybe I just learned to do this to avoid >kickback I don't know?
I also learned this technique somehow; maybe a friend suggested I try
it one time?
Pull the rope full travel or as much as possible. Don't short stroke it. >Let the starter rope retract quickly, Don't stand there holding the rope >handle. On a no start don't start the next pull until the engine has >completely stopped turning.
If I sense a kickback, I just let go of the handle.
Exactly what I do, and works great for my small engines. That first
pull is not a yank, it's a slow deliberate pull of the entire rope.
Highly recommended.
Old auto engines.
Started by hand crank. Some had no electric starters at all. We had a
1926 Daimler hearse refitted with a 1938 Bedford (i.e. UK GMC).
straight six engine, that had a defective starter AND a weak 1936
battery that had to be started by hand!
Ignition off.
Turn over engine slowly by hand through compressions of several or all cylinders to draw mixture into cylinders.
Retard ignition timing; by the control often mounted on middle of the steering wheel.
Pull compression up to near TDC.
Ignition on.
Pull by hand over TDC (watch your thumb position) and engine should
start.
Adjust ignition timing and drive off.
Fascinating! I've had several engines with devices that retarded the timing so that ignition occurred with the piston on the compression stroke close to top dead center: 4-cylinder A-65 Continental on an old '46 Taylorcraft airplane, for example. I
always hand-propped it on the Slick mag with the impulse coupling which retarded the timing to 5 deg. BTDC. Then once it was running I turned on the Bendix mag. Now the engine's mags are making sparks at 30 deg. BTDC, and timing is no longer adjustable.
Only fuel mixture is adjustable in flight.
My old kick-start '61 Panhead had timing retarded by twisting the distributor. As soon as it was running, a spring on the twist lever would pull the distributor around to fully advanced timing. Sometimes in city traffic I would retard the timing just
enough to stop spark knock from the heat of not getting enough air through the cooling fins, like waiting for a red light to turn green.
My old '68 BSA Spitfire also had a lever to retard timing, and another lever to adjust mixture.
Either one of these bikes would kick you over the handlebars, or bust the calf of your leg, if you did not watch how you started them.
It seems to me that the 10.5 hp engine would have some kind of automatic timing adjustment, or an automatic compression release to make starting easier. I have those devices on my old lawn mowers. And they're like me: old as dirt.
The object is to pull like hell, as fast as you can, to give the crankshaft enough momentum so that even when combustion occurs at 20 or 30 degrees BTDC, the crankshaft keeps rotating in the proper direction of rotation and does not kick back on you.
I've seen some younger guys hand-propping at the airport get hurt by not understanding those old magnetos, like the Bendix, which have no impulse couplings on them. All the line-boys at the airport are trained how to hand-prop, and they all wear thick
gloves.
That wind-up device on the Stihl reminds me of some old aircraft tech where elbow grease was used to crank up a flywheel, storing up potential energy which is then released by a clutch to give a quick series of rotations to the crankshaft and start the
engine. Some of those engines even used compressed gases from exploding cartridges about the size of shotgun shells to get an aircraft engine going. Remember that method in FLIGHT OF THE PHOENIX? They almost ran out of cartridges before the engine
fired.
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