Strange Problem With A MTD 21" Mower, Changed Blade Now It Kicks Back Like Crazy

drizler · Aug 21, 2014

Strange Problem With A MTD 21" Mower, Changed Blade Now It Kicks Back Like Crazy

This is just our el cheapo trimmer about 2011 vintage and it gets to knock through the nasty stuff along the edges of every place I don't take the big 5' trail deck I use. Yes this thing has nailed some big rocks as evidenced by the blade bent 1.5" straight down on one end. Still the thing started and ran find when I shut it off. All I did was drain the fuel flip it over long enough to change the blade and refill it.. Now the ugly little demon tries to rip my hand off every time I pull the cord.:thumbdown:. It kicks back every single pull with some worse than others. I tried pulling the plug and everything is smooth no hydrolocking on oil.
I have pulled the starter recoil assembly and it's perfect but that's all I have done so far. So what else could it be considering it hasn't hit anything lately. Am I looking at a sheared flywheel key that suddenly just decided to fall out of place when I flipped it over? Seems a bit far fetched to me

This thing ran like a top until then.
Of course it is all the worse because my wife is on my arse and squawking about buying a new one. I need to fix this thing fast before she drives me nuts.

drizler · Aug 22, 2014

Re: Strange Problem With A MTD 21" Mower, Changed Blade Now It Kicks Back Like Craz

I pulled that flywheel and it is pristine as is the key. Still kicks like a mule. I even removed the new blade and tried it NOTHING.

SPYDERLK · Aug 22, 2014

Re: Strange Problem With A MTD 21" Mower, Changed Blade Now It Kicks Back Like Craz

... So ... I gather the engine is firing early? The blade acts as a flywheel too - not slipping is it? Does it turn over smoothly if you pull slowly? ... Try maybe pulling slowly by feel til you reach the top of compression stroke. Then pull it hard. That way itll be turning pretty fast when it fires and should carry over TDC to the power stroke and go.

drizler · Aug 23, 2014

Re: Strange Problem With A MTD 21" Mower, Changed Blade Now It Kicks Back Like Craz

Weirdest yet it fixed itself. Only a Chinese lawnmower could pull that one off. Well, maby an old AMC car or two. No chit, I pulled the blade back off of it thinking it was the one thing I had touched when it happened and of course it still kicked. Then, this time using an impact wrench I put it back on and the thing took right off. The only difference was there was a drool this time from the front of the red pressure primer bulb. Nuts eh? Oh well , at least the Chinese junk lives to plow rocks another day.