On Tue, 13 May 2014 11:35:41 -0700 (PDT), jamesgang
wrote:

On Monday, May 12, 2014 5:41:19 PM UTC-4, wrote:
On Mon, 12 May 2014 13:47:23 -0700 (PDT), jamesgang

wrote:



On Tuesday, July 6, 2010 3:07:50 AM UTC-4, James H. wrote:

On Mon, 5 Jul 2010 23:53:26 -0700 (PDT), terry wrote:

Couple of years ago used to cost $3 to $4 around here.

Biggest job is often getting the blade off!



This video is from a very experienced lawnmower mechanic who advises

against removing the blade to sharpen it.

http://www.youtube.com/watch?v=HDQ0e...eature=channel



The owners manual recommends removing the blade if it's gonna be sharpened.

Why?



Why do all the manuals recommend removing the blade to sharpen it while

this admittedly very experienced mechanic says not to bother?



It's a safety thing. You can accidentally start the motor by turning the blade if the ignition is not grounded by an off switch of some sort. It's very uncommon but you know corporations have to make safe recommendations.

No, it is not an engine start issue - simply pulling the plug wire

eliminates that. It is so you don't skin knuckles, and so you can

balance the blade.

That's not the point. I realize you can make it safe. If they recommend sharpening it on the mower someone would not make sure it can't start and accidentally start the engine and then try to hold them liable. So they tell you to take the blade off first.
An awfull lot more likely to start the engine attempting to remove
the blade. Your reasoning just doesn't wash.
More likely to spill gas out of the tank and oil out of the crankcase,
or get the cyl full of oil, than start the engine.