John Deere JS46 Hard Starting Problem

mgilbert

Member
Joined
Aug 2, 2013
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I have a three year old John Deere JS46 walk behind mower with a Briggs Engine. The mower has had very little use. Lately, it has gotten harder and harder to start. Fresh fuel, clean air filter, new spark plug... It takes several hard pulls on the cord, and it usually just makes a ffffft ffffft ffffft sound, and it sometimes backfires. After a few pulls, it'll hit a time or two, then finally catch, miss some, slowly build up to speed, and then finally start running fine. If I shut it off hot, it is just as hard to start as it was cold. I'm not sure if this is related, but when it is running, the engine will often surge and run fast briefly when under load.

This engine seems to have an easy start feature that floats the valves to reduce compression when the cord is pulled??? If so, it almost seems as if the valve isn't closing so the engine can start. Sometimes, it acts as if it is flooded. I just can't any obvious problem.

Does anyone have any ideas?
 

mgilbert

Member
Joined
Aug 2, 2013
Threads
6
Messages
18
I have a three year old John Deere JS46 walk behind mower with a Briggs Engine. The mower has had very little use. Lately, it has gotten harder and harder to start. Fresh fuel, clean air filter, new spark plug... It takes several hard pulls on the cord, and it usually just makes a ffffft ffffft ffffft sound, and it sometimes backfires. After a few pulls, it'll hit a time or two, then finally catch, miss some, slowly build up to speed, and then finally start running fine. If I shut it off hot, it is just as hard to start as it was cold. I'm not sure if this is related, but when it is running, the engine will often surge and run fast briefly when under load.

This engine seems to have an easy start feature that floats the valves to reduce compression when the cord is pulled??? If so, it almost seems as if the valve isn't closing so the engine can start. Sometimes, it acts as if it is flooded. I just can't any obvious problem.

Does anyone have any ideas?

Really disappointed that so many people looked at this and didn't offer any advice... After checking everything, I began to think that it sounded like a timing problem. Turned out to be that the flywheel was a few degrees out of position because the key was sheered - a simple problem to fix!!! Keep that in mind if you ever run into something similar...
 

Fish

Lawn Pro
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Aug 2, 2013
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Sorry, most folks are out cutting their grass on Sat afternoon in Ky.....

Your post was only up an hour. Where in Ky are you, I am near Bardstown.

Fish
 

Fish

Lawn Pro
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ooooops, 13 hours....
 
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