Briggs and stratton problem

[duckmen1]

I got a used b and s 5 horse and it ran great the first two days. The third day it was running great half the day and then i started it back up and when i put it into gear forward it backfired and died. Now i cant get it to run, but once in a while i can get it to turn over for a minute but it backfires and dies before going into gear. Any thought or suggestions about the problem would be appreciated. Thanks

[fishingnut71]

some are a matter of time. Its not IF but WHEN. Thats my experience. They run great at first then all of a sudden whamo.

[jackmaster]

yank the plug and have a look see, check the oil.... then pull the fuel lines, it almost sounds like the fuel tank might be gummed up and you could have got some crap in the line, as long as you got spark you will get it runnin

[Mfowl]

Could be a deteriorating fuel line, my honda 4hp has that problem. Haven't found small enough hose clamps to replace it yet. Clean the carburator. Check the magneto as well.

[BigGoonTuna]

sounds like you may have a sheared flywheel key.

[sirfunkeybut]

sounds like you may have a sheared flywheel key.

  causing erratic and weak spark

[duckmen1]

I do know the fly wheel key is fine and so is the spark plugs. We thought for sure it was the fly wheel. The way it looks to me is something along the lines of the carberator and or fuel line because after ten or fifteen minutes of trying to get it going and giving it gas it runs for a few seconds but when you put it into gear or try to rev up it will die. Just like i am using any gas that made it through but it runs out. I put a new o ring seal into the lower unit of the carberator and blew all the hose lines out with a air compressor but still no luck. The oil was just replaced a week ago and looks great.
My fuel tank is a brand new 3 gallon tank from cabelas purchased two weeks ago for over fifty dollars. And the fuel line i bought the same day. But i will pull that line off the tank and try to blow it out to.
But another problem i see is when it was running the first two days it was have in nutral, put throttle to start mode, pump the hose and first pull started right up and ran great. Now i have to have it near idle to have a chance of it rolling over and starting for a second before it dies with it in forward gear. That should not be.
Thanks for all the help i will go back and retake it all apart and clean everything and see what happens.

[sirfunkeybut]

Choke issue? I know my 3hp Briggs and Stratton acts the same way but once it's warmed up it runs fine. I have to use starting fluid in the cylinder a couple times before it starts sucking feul through the carb, plus the choke moves in and out while running

[netcoyote]

You didn't say what the engine is powering but B&S used a lot of different carburetors on their line of engines. Some have floats and needles and some use diaphragms. Might be some others as well. I had a real problem recently with an engine that had similar symptoms. I got on to the information about the gumming that happens from the use of ethanol additives in gasoline. Talk to any small engine business and they will give you an ear-full about it. Whether you use ethanol free gas now or not, it sounds like this had some ethanol gas in it at one time and it set for awhile and gut gummed up. You would be advised to totally disassemble all the fuel components and use a carb cleaner and blow it out thoroughly. Replace any needle valves, or diaphragms with new components. ONLY use ethanol free gas in small engines. It's a bit hard to find, but it's out there. Use this link to find a location.
http://pure-gas.org/index.jsp?stateprov=WA

[duckmen1]

I know its not the choke thats causing the problem.
I am running it on a 16 ft johnboat and it is a 5 horse 4 cylinder engine.
I just checked all the fuel line leading into the carb. And it seems to be clear and getting gas to the carb fine. The over flow hoses are having gas come out know when i try to pull start it.
As far as gas goes i believe it has only ran regular unleaded gas. That might need to switch as you recommended. Thanks for that info.
It is getting good air flow also.
I think it might be in the carb itself. I have not completely disasembled it but i did drop the lower unit off and replaced a seal and didnt see any difference.

[sirfunkeybut]

Sounds like float might be stuck?

[smdave]

Have you tried starter fluid being misted into the carb while some one tries to start it? If it starts this will let you know its a fuel problem.

[Skillet]

Sounds like float might be stuck?

 

Pull the plug and see if it's wet.  If so, pump the bulb until fuel comes out the overflow, keep pumping just a little, then tap the fuel bowl with screwdriver handle.  That should do it if it's a stuck float.

[Mfowl]

Haha! My bad, I thought you were talking about a pot puller engine.

[fernsjd41]

Does is have a fuel pump on the engine? If the fuel tank is lower then the engine there's no way for the carb to pull fuel in, also usually when a small engine backfires under a load means it has water in fuel or fouled plug. Also the seat for the needle in the carb can get dirt in it and let it flood over or the seat can be bad and u need a new carb. Also if its dieing out under a load could have plugged jets in the carb due to old fuel or dirt in fuel. Maybe that will help...