# Flooding Crankcase 14 HP Briggs Engine Help



## junkyarddoggie (May 24, 2007)

Hello guys

I have a frustrating problem with my old riding mower. I've used it once this year and had a bunch of problems with it. I have most of them fixed at this point but have one problem that just won't go away. It's a Briggs 14 hp motor with the walbro carb. What it is doing is flooding the crank case after you shut it off. I have replaced the needle,cleaned the bore for the needle, checked the float and all is good. I suspect that solenoid on the bottom of the bowl could be causing the problem, but I don't know. I do know that solenoid plunger is supposed to pulled down to allow fuel flow when the key is turn on. I am thinking that mine is sticking in the down position allowing fuel to flow all the time. When I had it apart I tested it and it only worked intermittently. Am I on track guys ? I installed a fuel shut off in line so I could run the fuel out of the carb when finished mowing so I won't keep flooding the engine. That's a real pain in the butt and would like to fix it where I can run it without worrying about flooding. It empties the entire gas tank so I have wasted a lot of fuel, we all know that fuel can't wasted these days. I have to change the oil every time this happens as well. The crank case must be clean as a whistle inside, this last incident was about the 5th time now.

Thanks Mike


----------



## 30yearTech (Sep 14, 2006)

The solenoid on the carburetor will not cause this problem. It's there only to keep the engine from popping out the muffler when it's shut down and will not prevent a flooding carburetor from leaking fuel into the engine. The problem is either in the inlet metering needle, seat, float, fuel cap vent or carburetor vent. You could install an inline fuel cut off and shut the fuel off whenever your not using it and this will prevent this problem completely.


----------



## pyro_maniac69 (Aug 12, 2007)

yup, you've gone through the carb already, I would defiantly say that your solenoid is bad, they are about $30


----------



## pup1970 (Apr 2, 2008)

I agree with 30yrtech, You have "checked" your needle and seat, but a rubber seat that gets hard will cause your problem. The solenoid is a for prevention of fuel going throiugh the motor when the ignition is turned off preventing raw fuel to enter the exhaust and making a backfire. It will prevent fuel from flooding your motor oil but not intended for that. I believe you have a needle seating problem


----------



## The Joker (Feb 7, 2007)

Yup! I too agree with 30yeartech It's the metering needle, seat or float.


----------



## 30yearTech (Sep 14, 2006)

pyro_maniac69 said:


> yup, you've gone through the carb already, I would defiantly say that your solenoid is bad, they are about $30


Pyro, the solenoid will not prevent a flooding carburetor from filling with fuel and leaking into the engine, thats not the purpose of that part. It's strictly there to help prevent the after burn in the muffler when you shut down an engine.


----------



## junkyarddoggie (May 24, 2007)

The carb has a brand new needle installed and the seat is clean and smooth. I have already installed the fuel shut off last year, it's just a pain in the butt to use it that way. That machine has backfired through the exhaust the whole time I have had it, so that solenoid must be bad. I guess I will take it apart again and check the float again. It's a plastic float, there is no adjustment and the float pin is not bent. It would have to be the float, there is nothing else left. I found that solenoid in my Stens book for 45.00, where can I get it cheaper? My dealer price on the OEM part is even to expensive. I've already spent $200 this year and have only mowed once with this machine.

Thanks Mike


----------



## 30yearTech (Sep 14, 2006)

Did you make sure the fuel cap vent is clear?

Are you sure the carburetor float bowl vent is clear?

I have had carburetors flood with a seemingly good float, but when I installed a new float the problem was solved.

On engines equipped with the fuel solenoid, you should shut the engine off from mid to high throttle settings to prevent the "pop" out of the muffler when you shut it off. You don't even need the solenoid for your engine to run, if your engine is running alright.... Leave the solenoid alone as you won't see any improvement for your money. It's possible you may just have a bad seat in the carburetor, on some models they are replaceable on others it's a new carburetor.


----------



## dawgpile (Apr 28, 2008)

As 30YT indicated, I'd double check the float. I just finished a unit that had a bad float. Pinhole leak caused the float to be full of gas and needless to say, they don't 'float' too well with fuel in them as opposed to gas. Just remove the float and shake it. You'll know instantly if that's the cause. 

Also, have you actually removed and replaced the seat? I know you said it was smooth, etc. but it doesn't take much of an irregularity on either the needle or seat to let fuel pass. Inexpensive parts so they're worth replacing to be sure. You can remove the fuel line to carb, attach your own piece of hose and with the bowl off, float and needle attached, blow into the hose and lift the bowl to see if the needle is sealing off the fuel inlet.


----------



## pyro_maniac69 (Aug 12, 2007)

30yearTech said:


> Pyro, the solenoid will not prevent a flooding carburetor from filling with fuel and leaking into the engine, thats not the purpose of that part. It's strictly there to help prevent the after burn in the muffler when you shut down an engine.


I have seen carbs with bad solenoids flood right into the crankcase. And I knew the float was good (put it in water and looked for bubbles, none) and I knew the needle and seat were good because I replaced them both, and it still flooded, I replaced that solenoid, and it fixed everything. Thats just what I have seen on more than one occasion


----------



## 30yearTech (Sep 14, 2006)

pyro_maniac69 said:


> I have seen carbs with bad solenoids flood right into the crankcase. And I knew the float was good (put it in water and looked for bubbles, none) and I knew the needle and seat were good because I replaced them both, and it still flooded, I replaced that solenoid, and it fixed everything. Thats just what I have seen on more than one occasion


Once again pyro, not trying to be a smarty pants, but there is no way that the solenoid is going to prevent a carburetor from flooding. You have to look at the way the carburetor operates and if you do you will understand this. If you don't believe me, ask the service manager at your Briggs distributor, I am sure he would be happy to explain it to you. If you want to email me I will send you some info that will help show you. :thumbsup:


----------



## pyro_maniac69 (Aug 12, 2007)

I honestly understand where your coming from, I've actually wondered why it was the problem as well, but I'm just saying what I've seen, one of those things that will never be explained


----------



## 30yearTech (Sep 14, 2006)

pyro_maniac69 said:


> I honestly understand where your coming from, I've actually wondered why it was the problem as well, but I'm just saying what I've seen, one of those things that will never be explained


Most likely it was just coincidence that when you installed a new solenoid the flooding stopped.

The solenoid does not seal tight enough to stop fuel from being pushed up the nozzle under pressure, it's just blocks enough fuel from being sucked up when the engine is being shut off to help prevent an after fire (backfire). When a carburetor is flooding there can be 4 or 5 psi of pressure to the carburetor if the tank is full, eventually the gas will be forced up into the throat of the carburetor regardless of the solenoid valve. 

If the solenoid were faulty, chances are you could never get the engine to start and run. They are easily tested especially if it's the 2 wire type, just remove it from the carburetor (shut fuel supply off 1st) plug it back in and turn the key on, if the needle draws down with power and springs back up when the key is turned off, it's working. If you don't mind the bang when you shut the engine off, you can replace the solenoid with a regular bowl nut.


----------



## pyro_maniac69 (Aug 12, 2007)

I like bangs

its kind've like the bumper sticker that says "loud pipes save lives"

that and when you scare the S### out've someone when they are near you is always priceless also


----------



## junkyarddoggie (May 24, 2007)

I just repaired a mower for a customer where that solenoid was not getting power to it, and the unit wouldn't start. Turns out that the connector was full of crud over by the starter, easy fix.

The needle seat looks fine. It's one of those pressed in brass types, not sure how easy it would be to remove. Probably be a pain in the ass. I have done the old float in water trick and no bubbles in the water, nothing inside rattling around either. That backfiring scares my wife, she refuses to use it. she says it has too many quirks and procedures to follow to run it correctly. I don't mind the back firing so much, it's not worth spending 50 bucks on the part to fix it. I would like to fix the flooding problem. I'll fool around with it some more and let you guys know what find. Thanks for all the help, you guys are great.

Mike


----------

