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...

[duckmen1]

When pumping the fuel it has fuel going through the over flow hoses.
I have not tried starter fluid yet. I am going to have someone i know look at it in the next few days and bring up everything you guys said. Thanks for the help
I will let you know if i get it running. I do think it has to do with the carb though, i just dont know all that much about motors. It looks like if i need a new carb it will cost me 53 plus shipping

[duckmen1]

Got the motor running a bit after replacing the o ring on the carb bowl, but if i give it gas it backfires badly several times and wants to die. Like it may not be getting gas, but it looks like it is.
Got a carb rebuild kit but havent done so yet.
Any thoughts about the backfiring

[fernsjd41]

Sounds like it has a broke flywheel key or something is wrong wih the valves. Is it a overhead valve or flathead engine? Also did you take the flywheel off a make sure the key isn't partly sheared? The overhead valves like to back off on the studs for the rockers and bend push rods.

[motg9_6]

Fuel issue when putting the carb kit in blow out every port try soaking in carb cleaner overnite. This new fuel is GARBAGE as stated above. Try finding non ethanol will save a lot of headache in the future.

[Fl0und3rz]

Because you mention marine engine, it reminded me of an a problem an old friend had with an older merc 150 outboard. Same symptoms. Sluggish or died when going into gear or trying to accelerate.  After changing fuel lines, inline filter, carb rebuild, we found an engine mounted fuel screen housing that, once the screen was cleaned out, it cleared up all his problems. I don't suggest you have the same issue, but it does sound as if it is not getting enough fuel under load.

[duckmen1]

After listening to all hunt wa members as well as family and friends we tried many different things. The fly wheel key is fine, we replaced parts in the carb with a b and s carb rebuild kit and still had an issue. Then we took the two hoses and fuel filter off and replaced with just one hose no filter and it ran fine. I can blow air though the filter ok but assume that there is a bit of restriction in the filter. Runs fine now but plan on getting a new filter before too long and going to the ethanol free gas after this tank is empty as stated from many of you. I plan on going out within the next week and i will let you know how it goes. Thanks for the help

[motg9_6]

another thing i just thought of check the spark arrestor in the exhaust. if its plugged it will act like a fuel issue.

[duckmen1]

I will do that. But i did get the motor running after doing a carb rebuild and taking the fuel fuilter off with the two hoses and replacing with one straight hose. Will get a new fuilter though. And replace a few other things. Only cost a total of 13 bucks. Its still not perfect but i am off to a good start. The biggest problem im having right now is when i start in nutral and put it into gear it will die but i can start it right back up. Also i need to fine tune the screw that allows the gas/air mix so it wont keep backfiring every so often and be sluggish. I am going to put C foam in the gas also to help clean the engine. And am in the proccess of repainting it to clean it up a bit. But had it on the water all day the other day and was able to get it running throughout the whole trip with a bit of work.
Thanks for all the help and i will post next trip out of how the progress comes along.

[duckmen1]

Finally believe i found the biggest problem that has been causing everything after another frustrating day on the water. Armature magnito had a crack in the hose in between the sparkplug and the main part of the armature magnito letting spark escape at times such as putting into gear and reving the motor from vibration. wrapped with electrical tape to see what would happen and it is running perfect. Goes in and out of gear with no hesitation and idles to full rev without any problems. Even though other things needed to be replaced this was the main problem the hole time. As we were working on the motor and moving the hose from day to day that would cause the motor to run ok one day and vibrate back to problems the next. Glad to finally figure it out. I will by a new armature magneto in time. But cant wait to get it back on the water.

[motg9_6]

awesome congrats your now a specialist like the rest of us LOL

[duckmen1]

I will be leaving for the lake at noon so we will see how it goes. Have to fill up the gas tank and add a little sea foam and im good to go.