# Lawnmower won't start!



## LawnMachine (Jun 13, 2007)

We changed the spark plugs but the darn thing won't start. It's a lawn machine 14.5 horsepower briggs and stratton. In order to get it to at the very least turn over we had to jump start it. You would have to let it sit with jumper cables attached then try and crank it. It cranks sometimes, but nothing really fast. A couple of times it chugged and was running for all of 5 seconds then quickly shut off. I seen some smoke coming from out of the starter, so I'm assuming it's shot or about shot. I don't know if this was from the main cause or just a side effect of us trying over and over to get it to turn over. Any help would be greatly appreciated since I'm strapped for cash. Thanks!


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## hdman97 (May 25, 2006)

You may have cranked abit too much .
Ya Can't just keep trying if it don't start,that wiil just burn out the starter.
If you have spark then you may have a fuel problem.
Is the fuel fresh? Is there a fuel shut off? Now old is the mower? Are the blades ingaged? Do you have compression?
Sounds like at the very least you need a new battery.
Need more info.....


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## LawnMachine (Jun 13, 2007)

Brand new battery in it. The mower is about 5 years old. Fuel is good in it. Poured some fuel in the carbeurator and it wouldn't start.


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## 30yearTech (Sep 14, 2006)

Check the valve lash, too much clearance and the compression release will not work. Too much compression and you will burn out your starter trying to get it to turn over past the compression stroke.


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## LawnMachine (Jun 13, 2007)

what is a valve lash? I take it now's the time to take it to the shop


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## 30yearTech (Sep 14, 2006)

*Lash*

Just another way to say clearance. The clearance is checked between the rocker arm and the valve or between the valve and the lifter depending on the design of your engine.

A repair shop should be able to check and set your valve clearance for you, if thats the problem with your engine.


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## justin3 (Apr 10, 2007)

before you bring you lawnmower to the shop, take the starter motor off, bolt it to a desk, and jump it with a battery. The starter should go crazy with a mass amount of torque, very dangerious if its not bolted down. If the engine is having trouble turning over all the time and not just at the compression stroke, either the engine is partialy frozen or the starter and/or battery may be dead. I have a 14.5 sitting in my shed with a bad starter, same problem you had, it smoked and only turned over when I gave it the extra power of a car battery.


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## 30yearTech (Sep 14, 2006)

justin3 said:


> before you bring you lawnmower to the shop, take the starter motor off, bolt it to a desk, and jump it with a battery. The starter should go crazy with a mass amount of torque, very dangerious if its not bolted down. If the engine is having trouble turning over all the time and not just at the compression stroke, either the engine is partialy frozen or the starter and/or battery may be dead. I have a 14.5 sitting in my shed with a bad starter, same problem you had, it smoked and only turned over when I gave it the extra power of a car battery.


Hate to disagree with you justin3, but bench testing the starter with no load will not tell you if the starter is good or not. You can have a shorted field winding in a starter and it will still spin, just won't have as much torque. This also won't tell if there is any problem with the power delivery to the starter from the units electrical system (battery cables, solenoid etc..) which can affect the starters performance as well. 

An overhead valve engine as a lot more compression than an "L" head and if the valves are out of adjustment, a good starter will have trouble spinning the engine past the compression stroke. You can destroy a good starter trying to start an engine that is not properly adjusted. There are other reasons an engine can have excessive compression such as carbon build up, a flooding carburetor or a crankcase overfull of oil. 

As hdman97 described in his post, running the starter too long can burn one out. There is no cooling system or fan on a starter motor, if the engine does not start in a reasonable amount of cranking say 30 seconds or so, then stop cranking and let the starter cool down a few minutes before trying again.


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