I have a JS28 John Deere its always ran perfect 1st pull. All of a sudden it won't even try to start. Has new spark plug...tested it, it is getting spark. cleaned out the carburetor meticulously today. Air filter is clean. Gas tank is clean and so is fuel line. Gas is brand new. When I have the air box on the engine won't make a noise when I try to start it. With the air box open it will back fire out the carburetor several times. I'm not sure what could make a perfectly working mower go from working perfect then 15 mins when I try to restart it its 100% dead. Any suggestions would be appreciated.
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John Deere JS28 engine won't start out of the blue
- Thread starter ctepp
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Export threadbertsmobile1
Lawn Royalty
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- Nov 29, 2014
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broken con rod
Broken push rod
bent pushrod
dropped valve
Excessive valve lash finally allowed the lash cap to fall off
Cut out wire shorting against the engine
Want any more ?
Broken push rod
bent pushrod
dropped valve
Excessive valve lash finally allowed the lash cap to fall off
Cut out wire shorting against the engine
Want any more ?
Thanks. I have no clue past the things I've done so anything helps. Based off of this being a well maintained garage kept mower that never really has hit anything to jar it around would you start trying a certain thing or list of procedures? Would the spark plug fire if the cut off wire was shorted?
bertsmobile1
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Well maintained ?
When was the last time the valve lash was checked ?
Backfireing through the carb can be a lot of things from a stuck inlet or exhaust valve through to a broken flywheel key.
I would start with the valve lash.
Both valves are the same length and move the same amount so check that is happening.
around .004" on both should run.
When was the last time the valve lash was checked ?
Backfireing through the carb can be a lot of things from a stuck inlet or exhaust valve through to a broken flywheel key.
I would start with the valve lash.
Both valves are the same length and move the same amount so check that is happening.
around .004" on both should run.
I would guess never. The mowers around 4.5 years old and I was given it. Figured I would try to get it working to learn and try to save some money. Interesting learning experience. Thanks for the suggestion I'll do some research and check it when I get some time.
bertsmobile1
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That would put it on par with most of the ones I see.
A lot more to maintenance than just changing the oil & filters.
Briggs manuals are everywhere on line for free.
or ewe-tube
Donyboy , Taryl fixes all are two channels worth subscribing to.
e-replacement parts have some videos as does jacks Small Engines.
A lot more to maintenance than just changing the oil & filters.
Briggs manuals are everywhere on line for free.
or ewe-tube
Donyboy , Taryl fixes all are two channels worth subscribing to.
e-replacement parts have some videos as does jacks Small Engines.