Lawn Mores

[SW CQB 45]

When I was on patrol (years ago), one of my favorite areas to monitor traffic (OK, get speeders) was next to a business that said (spray painted on the side)

"Lawn Mores Repaired"

Alright... this is a sad story, but my fault.

My favorite mower that I got as a cheapo return from Lowes (150 for a 300$ unit about 2 years ago with a broken cord)

Troy Built with a 6.5 Briggs FWD, big rears met its fall yesterday.

I hit a pipe which stopped the blade and engine.

It fired back up, but with a puff of smoke and higher RPMs and excessive shaking.

From what I can determine, the blade shaft is not straight.

Am I SOL and hurt my "LAWN MORE" beyond repair?????

dont know enough about lawn engines.

I went to inquire about returned "mores" yesterday at Lowes and there was none or at least that what I was told.

I feel sick as there was nothing wrong with this mower. It was a small piece of pipe from a trampoline that was hidden in thick grass.

 

[Noah Zark]

Is the blade shaft the same as the engine crankshaft? If yes, then just "repower" the thing with an identical new engine from Troy Bilt or Northern Hydraulics or some other small-engine outlet.

If the blade shaft is independent of the engine crankshaft and most likely belt driven, then contact Troy Bilt for a replacement blade shaft/bearing quill assembly.

Either option is less expensive than a new mower, especially since that one has been a steady eddie for you.

JMO, but coming from the owner of a 25-yr-old repowered self-propelled Honda walk-behind that's like a certain drum-beating pink stuffed rabbit.

Noah

 

[kritter]

bent crankshaft or broken blade?, maybe bent blade?
any of the three can cause the "shaking"
now keeping in mind that an engine runs basically like a air compressor ,the sudden stop may have caused extra fuel to be sucked into the engine causing the puff of smoke at start up,, also causing the higher RPM's
I'm just suggesting before investing in a new mower , you might want to check the blade.we've had some around here that have hit treestumps and devloped a "death wobble" that was cured by a blade change

 

[41]

A solid hit probably sheared the shear pin on the flywheel and the timing is off enough to cause it to run ruff. Sometimes the shear pin will not break completely and still allow the engine to run and start poorly.

It is also possible that a valve is bent depending on the engine design.

I would take the blade off and see if it is bent or has a piece broken out of it that makes it out of balance. If so a new blade will solve the problem. In addition while the blade is off, you can start the engine and see how it runs.

41

 

[SW CQB 45]

OK, gives me something to look at.

I did inspect the crank or blade shaft while turning the blade and it does appear to be bent while turning.

but I will remove the blade and give it a closer look.

thanks

 

[cshoff]

I'd guess you either sheared the woodruff key that times the flywheel to the crankshaft, bent the crankshaft itself, or bent the blade. Of course, it's also possible you have done a combination of two or more of those things as well. Anything other than a bent crankshaft will be an easy fix. If the crank is bent, then the engine is shot and will require a new. You may well be able to purchase a new "lawn more" for what a new engine will cost you. Good luck with it!

 

[41]

"I'd guess you either sheared the woodruff key that times the flywheel"

Don't ever call the flywheel key a WOODRUFF KEY. Use a woodruff key and see what happens to your crank.

Get the correct shear pin or shear key from the engine manufacturer. It is made of soft metal to shear off and not hardened metal like a WOODRUFF KEY.

 

[cshoff]

"I'd guess you either sheared the woodruff key that times the flywheel"

Don't ever call the flywheel key a WOODRUFF KEY. Use a woodruff key and see what happens to your crank.

Get the correct shear pin or shear key from the engine manufacturer. It is made of soft metal to shear off and not hardened metal like a WOODRUFF KEY.

The word "woodruff" refers to the half-moon or "semi-circle" shape of the key. It has nothing to do with the hardness of the metal it is made out of. Woodruff is a design, not a hardness specification.

 

[Spotteddog]

Check what 41 and CS suggested first, IMHO?

 

[41]

The word "woodruff" refers to the half-moon or "semi-circle" shape of the key. It has nothing to do with the hardness of the metal it is made out of. Woodruff is a design, not a hardness specification.

I have never seen a WOODRUFF key used on the shaft to hold the flywheel in place. Here is a view of some of the type of keys.

http://www.huyett.com/catalog/index.php?cPath=22_51

The machine key shown is the usually shape of the shear key used to hold the flywheel in place on the crank. Machine keys can also be hardened. So just make sure you buy the part specified by the engine manufacturer.

From your post, someone would go to Sears Hardware or another hardware store buy the wrong key for his mower and in turn destroying the crank the next time he hits something. Had it happen to one of my neighbors and the expression on his face was priceless.

41

 

[Spotteddog]

I agree!
Typically while it may resemble a "woodruff" on some, it'll be made of Aluminum. More commonly, it may resemble a piece of "key stock" made from Aluminum. When checking it, look for rolling over of the edges of the cut in the crank for the key. It may need to be dressed up some. (Inside tip: Use anti seize compound on the taper of the fly wheel to guarantee easier removal later)

 

[cshoff]

I have never seen a WOODRUFF key used on the shaft to hold the flywheel in place. Here is a view of some of the type of keys.

http://www.huyett.com/catalog/index.php?cPath=22_51

The machine key shown is the usually shape of the shear key used to hold the flywheel in place on the crank. Machine keys can also be hardened. So just make sure you buy the part specified by the engine manufacturer.

From your post, someone would go to Sears Hardware or another hardware store buy the wrong key for his mower and in turn destroying the crank the next time he hits something. Had it happen to one of my neighbors and the expression on his face was priceless.

41

They make woodruff keys in varying hardnesses, from aluminum, to standard mild carbon steel, on up to hardened steel and stainless steel. Yes, I agree that you should buy the right part for your particular application. No need to damage the engine any further.

If the OP will post the Model, Type, and Code from his Briggs & Stratton engine, I will be happy to look up the original B&S Part number for him on the key or any other parts he may need.

 

[McGregor]

One other suggestion to go along with replacing the flywheel key is to get the right kind of puller to pull the flywheel. My son tried using one of the three jawed? type of pulley pullers and broke the flywheel into two pieces. Turned a $2 job into a $70 job.

Greg