I have a riding mower with an 18.5hp B&S model 31N707 0301 E1 engine. It was running fine till I stopped to empty the bags and she won't restart. It turns over and backfires. Flywheel key is good, replaced plug and tested for spark, replaced magneto, replaced fuel filter, cleaned carb, cranked with starter fluid and backfired louder. I have no idea where to look next. Any guidance would be appreciated.
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Was running fine. Emptied bags and won't restart
- Thread starter McDemon
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Export threadTinkerer200
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I would remove the valve cover and see that push rods are in place and working when you turn the engine by hand. When you turn the engine by hand does it come up on compression, have good compression? Turn the flywheel clockwise looking down on it.
You did turn the PTO off when you stopped? Does the carb solenoid click when you turn the switch on?
I can send you a Service Manual for your engine IF you like, address below, put in proper format and remind me engine model number and what you want.
Walt Conner
wconner5 at frontier dot com
You did turn the PTO off when you stopped? Does the carb solenoid click when you turn the switch on?
I can send you a Service Manual for your engine IF you like, address below, put in proper format and remind me engine model number and what you want.
Walt Conner
wconner5 at frontier dot com
Hi Walt,
Thanks for the quick response. I took off the valve cover and when I turn the flywheel, the rocker arms are moving smoothly and look to be undamaged. The engine makes a whistling, woosh sound once per revolution of the flywheel. Does that indicate a problem with compression or is that normal? I tested the solenoid and it opens under 12v. One other piece of info that I forgot to include in the OP; the first time the mower failed to start after stopping in the middle of the lawn, when I went to restart it I got nothing, no starter motor, no turn over nada. I let it sit for about 15 minutes then tried it again. She started fine and has not restarted subsequently but turns over. As far as the PTO switch is concerned, would that be the seat switch? The previous owner had disconnected it so I guess the answer to your question would be no, I didn't turn it off. I'll send you an email for the manual. Thanks much!
Matt
Thanks for the quick response. I took off the valve cover and when I turn the flywheel, the rocker arms are moving smoothly and look to be undamaged. The engine makes a whistling, woosh sound once per revolution of the flywheel. Does that indicate a problem with compression or is that normal? I tested the solenoid and it opens under 12v. One other piece of info that I forgot to include in the OP; the first time the mower failed to start after stopping in the middle of the lawn, when I went to restart it I got nothing, no starter motor, no turn over nada. I let it sit for about 15 minutes then tried it again. She started fine and has not restarted subsequently but turns over. As far as the PTO switch is concerned, would that be the seat switch? The previous owner had disconnected it so I guess the answer to your question would be no, I didn't turn it off. I'll send you an email for the manual. Thanks much!
Matt
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