# ys4500 problems



## temison (Sep 20, 2012)

I have a 3 year old ys4500, I have done routine maintenance, have replaced fuel/air/spark. fresh fuel. While running, engine stopped. The starter is spinning, gear engaging, motor is spinning, just not turning over. Change spark and filters, fully charged battery. Still the same, all spinning, not starting. I have read about cut off switches, solenoids ect. Any help out there????


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## Bill Kapaun (May 8, 2007)

ave you checked for spark when cranking?

IF you have spark, try priming the carb with 2-3 teaspoons worth of gas and see if it tries to fire.


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## wjjones (May 28, 2010)

The seat switch on these is usually the first one to act up. Also make sure the pto for the deck is pushed in/ disengaged.


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## Bill Kapaun (May 8, 2007)

If the PTO was engaged, it wouldn't crank.


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## temison (Sep 20, 2012)

O.K., so the starter starts, replaced spark plug. Checked spark plug, got spark. Checked valves, they are moving. It is getting fuel. I just don't have compression. Any ideas?


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## temison (Sep 20, 2012)

I have a 3 year old ys4500, I have done routine maintenance, have replaced fuel/air/spark. fresh fuel. While running, engine stopped. The starter is spinning, gear engaging, motor is spinning, just not turning over. Change spark and filters, fully charged battery. Still the same, all spinning, not starting. I have read about cut off switches, solenoids ect. 
O.K., so the starter starts, replaced spark plug. Checked spark plug, got spark. Checked valves, they are moving. It is getting fuel. I just don't have compression.


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## Bill Kapaun (May 8, 2007)

Posting the Sears 917.xxxxxx number or engine Model & Type/spec would at least allow one to know WHAT engine you have.

I'll ASSUME it's a Briggs 311877-0805-E1

IF so, remove the valve cover and look for a bent/loose pushrod.


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## wjjones (May 28, 2010)

Bill Kapaun said:


> If the PTO was engaged, it wouldn't crank.


 Your right I forgot the whole system is locked out with the pto engaged at start up.


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## temison (Sep 20, 2012)

I have a craftsman ys4500 that has stopped working. The best it will do is the starter flywheel spins, motor spins, no ignition. I have changed the Fuel filter, air filter, changed spark plug(have spark). Set the valves to .004, inspected the rod pushes. Changed fuel and oil. By checking at the spark-plug hole, I don’t seem to have any compression. What I do know of motors, is that with no compression, no starty. What next???? Of coarse this happens after the warranty expired.


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## wjjones (May 28, 2010)

The intake valve is .004 but the exhaust valve is .006. Do you have a compression tester?


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## dangeroustoys56 (Jul 26, 2010)

As mentioned, if the valves arent working/stuck open , theres no compression- they can be operating and still not close fully ( valve seat fell out- for example) - could be the rings are 'stuck' , air goes past the piston and no compression - it couldve even thrown a rod.

Ive had a motor turn over, and wouldnt start- so i turned the motor by hand with plug out and a small screw driver in the hole ( touching top of piston) - piston didnt move at all - rod had broken just right to let it do that.


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## wjjones (May 28, 2010)

I have seen the valves stick shut, and or open too. I have heard they make an additive that will help loosen them up but its got to be running to do that.


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## dangeroustoys56 (Jul 26, 2010)

I use good old PB blaster - spray the bejeebus out of the combustion chamber and let it soak for a day - best thing about it is the tractor will run with it in there, so no need to clean it out.


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## wjjones (May 28, 2010)

dangeroustoys56 said:


> I use good old PB blaster - spray the bejeebus out of the combustion chamber and let it soak for a day - best thing about it is the tractor will run with it in there, so no need to clean it out.


 Good idea.


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## dangeroustoys56 (Jul 26, 2010)

Yeah i nearly seized a briggs motor couple years back , stuff saved the motor - took like 4 days of continually soaking it tho.


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## wjjones (May 28, 2010)

Did you get it figured out yet temison?


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## temison (Sep 20, 2012)

Looking at pulling the piston to see if it is O.K.


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## temison (Sep 20, 2012)

Piston is intact, but the chamber is completely black crusted over. Will clean, recheck cylinders .004 to .006. Then try again.


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## wjjones (May 28, 2010)

temison said:


> Piston is intact, but the chamber is completely black crusted over. Will clean, recheck cylinders .004 to .006. Then try again.



Ok keep us updated..


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