power washed lawn mower and now it wont start, backfires bad

hiii98

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  • / power washed lawn mower and now it wont start, backfires bad
I power washed my lawn mower with it being off. Started it back up and drove it into the shed, the next day I go to start it and its is backfiring terribly, difficult to start but does barely manage to start. It then acts as if it has 1/2 the power it had before, and the blades barely turn. Today I try to start it and all it does it turn the motor over and over and over, with a random LOUD backfire here and there but will not start. I drained all the gas, put in a new fuel filter, and a new spark plug. I poured in a bottle of ISO HEAT water remover too (before draining the old fuel and iso heat additive)... I'm frustrated and the grass now is embarrassingly tall. I have no idea where to start to diagnose this.

there is only 1 spark plug and its a 16hp motor.
 

ILENGINE

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  • / power washed lawn mower and now it wont start, backfires bad
You didn't say what kind of mower you have or what engine is on it. Could you please post the information so we are more equipped to assist you.
 

Vervepipes

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  • / power washed lawn mower and now it wont start, backfires bad
You could try to isolate whether it's an electrical fault or fuel related by spraying a bit of carb cleaner or gasoline into the air intake. If it starts right up and dies/sputters after a few seconds then you likely have a fuel issue, if it won't start at all the pressure washing likely disturbed something in the ignition system. Give that a try
 

shiftsuper175607

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  • / power washed lawn mower and now it wont start, backfires bad
I power washed my lawn mower with it being off. Started it back up and drove it into the shed, the next day I go to start it and its is backfiring terribly, difficult to start but does barely manage to start. It then acts as if it has 1/2 the power it had before, and the blades barely turn. Today I try to start it and all it does it turn the motor over and over and over, with a random LOUD backfire here and there but will not start. I drained all the gas, put in a new fuel filter, and a new spark plug. I poured in a bottle of ISO HEAT water remover too (before draining the old fuel and iso heat additive)... I'm frustrated and the grass now is embarrassingly tall. I have no idea where to start to diagnose this.

there is only 1 spark plug and its a 16hp motor.

The air filter is soaking wet?
 

hiii98

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  • / power washed lawn mower and now it wont start, backfires bad
The air filter is soaking wet?

no

" it won't start at all the pressure washing likely disturbed something in the ignition system. Give that a try "

I tried that, and that just causes it to backfire ALOT worse than before... it will not start however even with ether

I also left for a week and came back today to start it, and the same exact problem. it has all new fuel in it. not sure if the carb is the problem or if it has some sort of electrical system that I somehow fried.
 

Mikel1

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  • / power washed lawn mower and now it wont start, backfires bad
Not sure what mower you have but have you checked the valves? A valve could be sticking open.
 

hiii98

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  • / power washed lawn mower and now it wont start, backfires bad
how do you check the valves? easy process? just backfiring real loud when I try to start it now. its a riding lawnmower 16hp. I'll post brand/model later.
 

Mikel1

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  • / power washed lawn mower and now it wont start, backfires bad
You can check the valve clearances, also you can visually watch the movement(travel) of the valves while turning engine by hand. Leakdown tester would be the easiest but most people don't have one, also have to have an air compressor.
 

gfp55

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  • / power washed lawn mower and now it wont start, backfires bad
First, you need to post more info about your mower so folks don't have to guess. Post what kind of mower you have, model number, serial number and maybe a picture of it also. You are asking for help but are not helping by not giving important information. Do you know what kind of mower you have? Is it a push mower, a zero turn, a rider? tell us more.
 
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