Lawn Mower Repair – Won’t Start After Rain – Water in Fuel

This is a Briggs and Stratton 355ex Lawn Mower 140 cc Engine. After 4 days of rain, even with the mower covered, it would not start. I go through the troubleshooting process to fix the issue and found water in the fuel.

I removed the Fuel Tank and Carburetor Bowl to find the water mixed in with the gas.

This is a great Average Guys Garage fix. Do it yourself and save all the labor costs.



21 thoughts on “Lawn Mower Repair – Won’t Start After Rain – Water in Fuel

  1. thank you very much!!!!!i totally forgot to check the carburator bowl!i checked the spark plug took it off to see if there was oil in the engine.cranked it to see if any oil came out and nothing..thank you again brother!ill check the carb tomorrow!

  2. Hi good video…….. but, After you put fresh fuel in the tank, I'd grab a bottle of gas line Antifreeze. punch holes in the cap and squirt some the fluid in the tank. this will take the moisture away from the bottom of your tank.

  3. Thank you for your video! I used it to work on my mower today and even though the gas was fine, I guess something I did cleared it and it started right up. It was blowing white smoke and then just stopped this morning. I thought it might be oil in the carburetor, the sparkplug did need cleaning. Anyway, I was ready to junk the mower and take it to the dump. You saved me the $75 I paid for it a month ago.

  4. i found out it was my gas can that was getting water in it… its funny that i didn't catch onto it that i have not filled up that gas can in a long timise… everythime i went for it to fill up the lawnmower, it always seemed to be full…. this is what happens when you don't pay attention to the signs …

  5. Thank you, mine was the bowl with little water in the carburator bowl, not much, maybe 1 tablespoon. I will advise to start troubleshotting at the carburator bowl if you left it out in the rain. I also removed the spark plug as there was some water in the combustion chamber. then just cleaned the plug good and wetted with gasoline and installed. those two things made it work.

  6. I own that same mower and I removed, disassembled and cleaned the carburetor and now it wont start. What should I do? Before I removed the carburetor the mower was extremely hard to start and it ran very low. Why would it do that?

  7. nothing happened between this week and last week except that it rained……….. it rained and also I smashed the lawn mower so hard on something that the gas tank cracked

    but thank you

  8. thank you dude, my kid put a gas can of water in my tank and this video showed me exactly how to fix it, you saved me from getting another mower or a huge repair bill, thanks a billion

  9. These carbs have a drain plug in the float bowl. It's a 10 millimeter Allen but because of the design, it might be hard to get to, depending on the mower deck. Turn the plug one quarter CCW and it comes right out.

  10. Water spark plug could be oil fouled indentified by wet black deposits on the insulator shell bore and electrodes caused by excessive oil entering combustion chamber through worn limit wear rings and pistons excessive clearance between valve guides and stems or limit wear loose bearings can be leaned it engine is not repaired use a hotter plug …………

  11. I saved an old Victa Powertorque mower from a rubbish collection which had been sitting out in the rain.

    The engine was full of water as it had been sitting in the rain & Victa still position the air cleaner assembly on the top of the push handle.

    The rubber bits on the carbys kill switch was deteriorated so was shorting the leads out so I had no spark.

    I tested the engines compression after spinning the engine out & letting it dry out for 24 hours, it tested at 107 PSI after removing the decompressor & plugging the hole,so it's a runner.

    I just added fuel through the inlet & it fired over for 10 seconds, I refitted the carby but it leaked fuel as the primer bulb plate is deteriorated,so the carby needs to be rekitted as well.

    I'll get it fired over with a rekitted carby but the engine still needs to be stripped down as it needs new crankshaft bearings due to water damage.

    So,I'll do that,replace the wheel bearings, lawn mower blades & repair a rust hole in the deck by welding a new piece of metal in.
    I am looking to paint the motor silver & the red base gloss black,anyhow,I"ll have a good mower after that.

    I have a Briggs & Stratton powered one which needs new rings,after that,I'll paint that motor gloss black & the Victa will be a backup mower.

    I just need to find a catcher for both,failing that,I could probably make one out of Hessian material !!!!

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