Subject: Re: [Shop-talk] Rock 1, Mower 0 ?

From: Jeff Scarbrough <[email-masked]>
Date: Mon, 20 May 2013 07:45:44 -0400

On Mon, May 20, 2013 at 6:34 AM, Eric J Russell <[email-masked]> wrote:
> shouldn't the engine manually rotate 360
> degrees smoothly without the blade?

With the plug out, I would think so.  I recall that there's a large
counterweight inside the motor that could have become
dislodged...could be what you're feeling.

It's fun and educational to take one apart, and they are pretty
simple.  You have nothing to lose but an hour or so, and it might be
repairable.

Jeff Scarbrough
Corrosion Acres, Ga.
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From: [email-masked]
Date: Mon, 20 May 2013 08:54:17 -0400

> Hit a large rock the lawn mower. (Briggs & Stratton engine in a Craftsman
> (snip)
> I assume the blade has some balancing/flywheel affect but shouldn't the
> engine manually rotate 360 degrees smoothly without the blade?
>
> Ideas?
>
Depending on how hard those tight spots are, you might only be feeling the
cam lobes against the valve springs.

Greg G.
Osseo, MN

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From: Pat Horne <[email-masked]>
Date: Mon, 20 May 2013 08:49:47 -0500

Thusly spake Eric J Russell

Years ago I did the same with a B&S mower. The end of the crank where 
the blade attached had about 1/8" run out, so I figured the engine was 
toast. Just for grins I tried to straighten the crank by using a 
suitable pipe to bend it back onto line. It worked, and I used that 
mower for several years until I moved and didn't take it with me. I know 
it can be unsafe, but it worked and didn't cost anything!

Running the engine without the blade doesn't always work because the 
blade acts as a flywheel. Running without the blade makes the engine 
speed changes faster than the governor can respond. This might be what's 
happening when the engine doesn't rev correctly. You might be able to 
hold the throttle linkage between the governor and the carb so that it 
revs up more.

Peace,
Pat

> Hit a large rock the lawn mower. (Briggs & Stratton engine in a Craftsman push
> mower) Bent the blade & sheared the key in the 'blade adapter'. The flywheel
> key is intact. With the blade & spark plug removed I can manually turn the
> engine but it feels like there are two unequally spaced tight areas with each
> revolution. The engine will run but it knocks & doesn't run at full speed.
>
> It is old enough that I don't want to bother wasting money on it (like a new
> blade adapter & blade) if it is likely fatally damaged. I assume the blade has
> some balancing/flywheel affect but shouldn't the engine manually rotate 360
> Eric Russell
> Mebane, NC
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>

-- 
Pat Horne, Owner, Horne Systems
(512) 797-7501 Voice & Text	5026 FM 2001
[email-masked]	Lockhart, TX 78644-4443
www.hornesystemstx.com
-- We support Habitat for Humanity - a hand UP, not a hand OUT --
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From: Brian Kemp <[email-masked]>
Date: Mon, 20 May 2013 15:49:08 -0700

Eric - Are you trying to run it without the blade?  If so, that might be 
part of the problem.  Check the blade for balance on a nail and it it is 
close, get a new shear key and put it back together to see how it runs.  
If the blade is badly bent, don't cut anything. If it runs normal, go 
for the new blade.  If it is bad, you can play with it in the shop or 
move on to a new mower and just be out the cost of the shear key.

I hit a small stump in leaves decades ago and broke the shear key. I 
replaced it and sharpened/balanced the blade and used the mower for a 
bunch of years.

Also check the bolts mounting the engine to the deck, but if the shear 
key worked, everything above it should be fine.

Brian

On 5/20/2013 3:34 AM, Eric J Russell wrote:
> Unsubscribe/Manage: http://autox.team.net/mailman/options/shop-talk/[email-masked]

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From: "Eric J Russell" <[email-masked]>
Date: Mon, 20 May 2013 21:42:18 -0400 a=z4AD9PZc4uoA:10 a=P2oOn6vrs4wA:10 a=8nJEP1OIZ-IA:10 a=S2wpYzp2RsyRkoRNwqcm1Q==:17 a=p50Rgy5_AAAA:20 a=20LRieseYUQQb3x_DSsA:9 a=wPNLvfGTeEIA:10 a=S2wpYzp2RsyRkoRNwqcm1Q==:117 reip=0.000, cl=1, cld=1, fgs=0

> Hit a large rock the lawn mower.

Thanks for the many replies.

To answer the questions/suggestions raised - the spark plug was out when I 
turned the engine by hand. The resistance I feel might be the valve springs. 
It seems the consensus is to try either a new blade or at least a roughly 
straightened/balanced old blade and see how it runs. The key in the blade 
adapter is (was) integral to the part. It is an aluminum part with the 'key' 
punched in from the side. I might try just bolting it together (without a 
functioning key) to see if it runs better with the blade.

I saw this on You Tube: http://www.youtube.com/watch?v=wjSZu2hlmsk I do have 
an assortment of hammers...

Eric Russell
Mebane, NC 

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From: Dave C <[email-masked]>
Date: Mon, 20 May 2013 19:23:52 -0700

Sorry for the late reply.

I made a "ditch mower" to run on an outrigger bolted to my tractor 
bucket.  It was essentially just a mower deck and motor bolted to a long 
arm.  I used it a couple of summers then hit a big rock.  I was able to 
straighten everything out and get it to run again but the crank runout 
and vibration wallowed out the main seal in pretty short order and all 
the oil ran out.  That pretty much killed it for good.

I'm going to make another one  some day, and  use heavy duty nylon 
strings or rods instead of a solid blade, like a ho-made DR Mower. I may 
even just buy a DR Mower head and work back from there.

On 5/20/2013 6:42 PM, Eric J Russell wrote:
> To answer the questions/suggestions raised - the spark plug was out 
> when I turned the engine by hand. The resistance I feel might be the 
> valve springs. It seems the consensus is to try either a new blade or 
> at least a roughly straightened/balanced old blade and see how it 
> runs. The key in the blade adapter is (was) integral to the part. It 
> is an aluminum part with the 'key' punched in from the side. I might 
> try just bolting it together (without a functioning key) to see if it 
> runs better with the blade.
>
> I saw this on You Tube: http://www.youtube.com/watch?v=wjSZu2hlmsk I 
> do have an assortment of hammers...
>
> Eric Russell
> Mebane, NC _______________________________________________
>
> [email-masked]
> Unsubscribe/Manage: 
> http://autox.team.net/mailman/options/shop-talk/[email-masked]

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From: "Eric J Russell" <[email-masked]>
Date: Wed, 22 May 2013 20:29:06 -0400 a=q7S00o-5r64A:10 a=P2oOn6vrs4wA:10 a=8nJEP1OIZ-IA:10 a=S2wpYzp2RsyRkoRNwqcm1Q==:17 a=xwPayol1AAAA:8 a=zOoktvdPAAAA:8 a=p50Rgy5_AAAA:20 a=CmCnrXBzdkjahClVNIwA:9 a=wPNLvfGTeEIA:10 a=0Ob1RWNGeVAA:10 a=S2wpYzp2RsyRkoRNwqcm1Q==:117 reip=0.000, cl=1, cld=1, fgs=0

For $20 I bought a new blade adapter & blade. Before installing them I 
propped the mower up on its side and used the Redneck Dial Indicator (tm) to 
check for run out of the crankshaft under the mower's deck. (I clamped a 
scrap piece of wood across the bottom of the mower and a second cut off 
aimed at the crankshaft's end.) With the spark plug removed & turning the 
engine by hand I could see the shaft wobble by ~ 1/8".

I next tried a length of pipe as a lever to try to move it back into 
place.My pipe was only about 18" long and didn't give much leverage.

Figuring I had little to lose, I marked the wobble with some chalk and 
positioned the shaft so I could whack it with a BFH. A few moderate whacks 
didn't do anything. A more forceful whack did the deed! No more wobble and I 
noticed the engine seemed to turn easier. (I do think the resistance I do 
feel is the camshaft operating the valves.)

I then installed the new blade adapter & blade and started it up. It ran 
fine, no smoke, no vibrations or bad noises. When I shut it off it coasted 
to a stop like usual - vs the sudden stop when I ran it a few days ago 
without a blade attached.

Eric Russell
Mebane, NC

----- Original Message ----- 
From: "Eric J Russell" <[email-masked]>
To: "Eric J Russell" <[email-masked]>; "shop-talk" 
<[email-masked]>
Sent: Monday, May 20, 2013 9:42 PM
Subject: Re: [Shop-talk] Rock 1, Mower 0 ?

> turned the engine by hand. The resistance I feel might be the valve 
> springs. It seems the consensus is to try either a new blade or at least a 
> roughly straightened/balanced old blade and see how it runs. The key in 
> the blade adapter is (was) integral to the part. It is an aluminum part 
> with the 'key' punched in from the side. I might try just bolting it 
> together (without a functioning key) to see if it runs better with the 
> blade.
>
> I saw this on You Tube: http://www.youtube.com/watch?v=wjSZu2hlmsk I do 
> have an assortment of hammers...
>
> Eric Russell
> Mebane, NC 

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