James H. wrote:
On Mon, 12 Jul 2010 13:44:23 -0400, Tony wrote:

you should come to the realization that you have no
knowledge and no apparent learning ability for basic mechanics and
physics.

Well, I've taken Physics 101 in college, so, I have a basic
understanding of static and dynamic friction. But I don't disagree
that the explanations given so far are, shall we say, problematic.

So far (please correct me if I state this incorrectly), we have
(only) two different reasons proposed for banging down on the
crankshaft.

1. The vibrations loosen the fit between the flywheel and the
crankshaft.

2. Moving the crankshaft down 1/8th of an inch, in effect, moves the
flywheel up 1/8th of an inch.

Assuming these are the only proposed reasons (again, correct me if I
err), I reply that both answers are "understandable"; but both are
problematic.

The problem with hypothesis #1:
- If vibrations are what we're after, we could just as well (and
perhaps more safely) smack the red shroud on the lawnmower; or smack
(lightly) the flywheel itself; or smack the sturdier lawnmower blade.
I guess vibrating the crankshaft from the top is easier than
vibrating the crankshaft from the bottom; but what I'm saying is that
vibrations don't have to come directly from the top of the
crankshaft. In my case, it wasn't anywhere near as successful as
simply pulling the flywheel up.

The problem with hypothesis #2:
- If moving the crankshaft DOWN is the goal, well what do you do when
you're done? Now your crankshaft is 1/8th of an inch too low. Do you
pop it back up from the blade side? If I understand the engine
correctly, the flywheel is on one end of the crankshaft and the blade
is on the other, with the piston in the middle. If you move the
crankshaft down 1/8th of an inch, aren't you moving the entire
apparatus down 1/8th of an inch? Don't you have to then move it back
UP 1/8th of an inch?

Having said all this, I do recognize MANY people bang down on the
crankshaft (just as people kick the tires of used cars for some
reason); I just can't fathom any practical reason for the type of
engine that I have (which is designed to be removed by tapping the
pre-existing flywheel holes and pulling up leveraging down on the
crankshaft).


Whoosh!!!!