Gas in the oil. How did it get there – a bad fuel solenoid/float. needle seat

Carlsbad small engine and ask the mower guy shows you in this video by harold what to do about a bad needle and seat and anti back fire solenoid( bad fuel solenoid) on your Briggs and Stratton riding lawn mower and what hydraulic lock means, and what happens if you have a sticky float and they all fail. The float ultimately will push up the needle into the seat but that may not be the only failure. Clean both the needle seat, small rod connecting the float to the carb and the solenoid.

If you liked our show be sure to please come by our online store!



23 thoughts on “Gas in the oil. How did it get there – a bad fuel solenoid/float. needle seat

  1. Question: My ariens mower is doing the same thing. Gas in the oil. I drained the oil/gas mix. Took the solenoid out and it was stuck down. I cleaned it real good and it went back up as it should. I hooked it back up and no gas in the oil now but it only runs for a quick sec after sitting then shuts off. Any suggestions?

  2. I just determined this is what was wrong with my mower. I believe it actually caused the blown engine (maybe bad rod?) about a year ago. I had the engine rebuilt n but apparently this wasn't taken care of. Hydrolocked and when I drained the oil and gas, it ran again. What about using a fuel shutoff valve in line on the fuel line, could that work too? Might save $50.

  3. so it`s safe to say if you have a pretty weak battery that the engine will bog when you engage the pto???? mine will bog and come back over and over, then i took the float bowel off and now nothing runs right, any web site have the parts for the same carb you was holding?

  4. Wrong, that solenoid is the anti backfire solenoid. Some people actually cut the pin off or remove the rubber cap if the engine is hard to start. If you are getting excessive gas into the carburetor (I had this problem) it is either a gas logged float, stuck / dirty or bad float needle. The needle controls the gas flow into the carburetor period. Clean or rebuild your carburetor. Ugg bad bad advice.

  5. Last night i tore my mower apart to the point of the head being off piston and was about to remove the barrel to check piston ring wear even though the cylinders were smooth…your video saved me about an hour of my life just by watching it and checking this carb out first…thanks so much.

  6. Really informative video! Thanks for that explanation… I think I might have a locked engine (Volvo) due to trying to crank the engine too many times and getting fuel in the cylinders.

  7. had this same junky nikki. the noid lost its seal at the electric part, and gas was pouring out the bottom. 100 bucks is to much to replace, i put a bolt in it. runs great.

  8. Wow…I'm glad this guy never worked on my machine…those plastic inserts in the Nikki's warp and will no longer seal no matter what you do.  To fix it correctly, which is what he is suppose to do and the customer expects, is to simply replace the carb.  It takes .25 labor and the cost of the carb…vs the 1 hr. labor and MAYBE the carb will last another season.  the cost isn't much more to fix it right for the customer…which brings more customers…and the other comments regarding the solenoid has nothing to do with it are correct.  The plastic insert leaks around the needle valve inlet so even if the needle seats, it will leak by the O-ring at the needle seat that the plastic insert sets on.

  9. thanks for showing how it work. I wonder why I put gas in the tank n 1 week past by n find it empty. order the part for this but trying figure how to start a hydrolock like u say …

  10. then mine has to be bad it drips gas at the red wire mine don't have the rubber tip.

    I park my mower on a slant to help it stop leaking the gas from the solenoid wire right now tho it's like a broke down car it'll crank over all day with no spark it seems like but then when it gets a jump it starts up. sometimes it'll blow oil and gas out of the muffler.

  11. The plastic needle valve has a spring inside that can get stuck in the compressed position preventing the valve from closing. This would create the overflow of gas into the crankcase as well. Mine is a 12.5hp intec with a NIKKI carb circa 2005 model. Replacing the needle valve with a new one should fix the problem.

  12. thankyou your info is golden 20 horse briggs single same thing old gas pluged up PS. is there anyway you can get closer to the products on your videos small parts are hard to see but i got the info

  13. Installing a manual fuel shutoff directly before the carb inlet will prevent 90% of this. My 22HP Kohler SV715 has the same issue. The key thing here is the cylinders are not filling with gas while the engine is running, it happens after you shut down and the needle is leaking and it slowly siphons through the fuel pump. This is not an issue if your fuel tank sits at a lower elevation than the carburetor as gravity can't allow siphoning but on the Cub Cadets and a few others the fuel tank is right under the steering area and a bit higher than the carb! Think about it, a leaking needle and seat would only be an issue while the engine is off and sitting, while it's running you won't notice a leaking needle seat because the needle will be open letting in fuel anyway.

  14. Thanks a lot for posting the vid!  My mower was smoking up the hood all of the sudden.  It would run but smoke really bad, the plug would obviously foul up and aaalmost shut off but then I guess the plug would dry enough to fire more, then more clouds of smoke.  I had never done it before, I thought it was a blown gasket so I ripped into it thinking, "Oh man, how am I going to get this back together, what am doing?!"  I took the head off, took it to a small engine shop, "Looks OK to me but sounds like you busted a ring.  "My mower IS 20 years old."  "Oh yeah, it's junk, you have yourself a good boat anchor."  I was skeptical.  So I put the head back on and decided to check the oil, expected to see the stick dry but it was waaaaay too full.  I got paranoid, thought one of the neighbors sabotaged my mower, "Son of a diddly, who would do that?!"  I drained the oil, it was like water, seemed like half a gallon.  It was gas and oil.  I read of what the problem was so I went to autozone and bought a $5 shut-off valve and installed it right after the fuel filter.  I will shut the valve and let the gas get used up that is still in the line when I'm done mowing, only takes about 20 seconds for the rest of the gas to leave the line after the valve, then remember to turn off the ignition switch.  I'd do it the "right" way but this thing is old and not worth much.  Then I saw your vid here, really appreciate the detailed explanation.

  15. The reason for gas going back in the crank case is that the SEAT I REPEAT SEAT is bad not the anti backfire noid like in the video. Kohlers and Briggs are famous for that problem. There is a fuel pump on the side of the engine and the vacuum from the crankcase will suck the fuel from a leaky carb that has a bad SEAT since the fuel pump works off of the crankcase vacuum pressure.

    Tanks that are above the engine are gravity fed and no fuel pump is required.

    Seats in Kohlers and briggs have to be taken with tools that are homemade mostly. I make my own.

    If the anti backfire solenoid is bad AND leaking gas from the bottom of the carb then take it out and save 80 or 90 bux and put a regular bowl nut in it. Always idle the engine down for 5 seconds and then turn the key off. NO BACKFIRE that way or maybe one small poof now and then.

    I have done this many many times. I will post a part number for the bowl nut later.

  16. thanks for sharing a very informative video, I know some people disagreed with your advice and that's ok, I, in the other hand found more sense in how you explain the gas and oil issue.. once agin, thanks for sharing this video.

Leave a Reply

Your email address will not be published. Required fields are marked *