Small Engine mechanical help needed...

[Stanley Steamer]

for the Wife's Grandma's mower.....it's a small Briggs and Stratton 4H Quattro pushmower...It's not but a few years old, but has the "handle brake" and no choke lever....just the prime bulb above the gas tank....it'd start up and run a few seconds before dying out....I put a new spark plug and air filter on it, cleaned all the gunk off of everything, took the gas tank off to make sure the screen wasn't clogged up, took the cover off and polished the mating surfaces of the flywheel to the dooomahicky that is connected to the other end of the spark plug....blew all the old grease and stuff off all internal surfaces while I had it apart....put it all back together and it still runs for a about 10 seconds and dies out.....if you continue to push the prime bulb, it'll perk back up for a few seconds.....that's what made me think it was a gas issue...I had already put a little seafoam in there when I topped the gas off.....I gapped the spark plug a couple of different ways to no avail....I didn't know what else to take off and look at.....any ideas??....

[junior]

wouldnt you have better luck on a harley board?

 mine has a choke its on the front of the motor its a little lever i would check there stan and if that aint it the jet needs to be adjusted

[Scott from FL, now in Maine]

Check the venting for the tank.  Some tanks have a seperate vent, others are just holes in the fill cap. They are small holes and do get clogged on occasion. If clogged the tank forms a vacuum and fuel flow stops. 

[Stanley Steamer]

unless I'm blind(not yet even though I wear glasses for long distance vision), then the only thing on the front is the throttle....I think the prime bulb replaces the choke on these new mowers.....now the venting on the tank is something that had crossed my mind...I'll look and see if the vents in the gas cap are clogged up or if there is a seperate vent somewhere on the tank??...any ideas of where it'd be??...it's just a smal one quart tank...thanks for the help...

[Scott from FL, now in Maine]

most just vent in the cap, but if the vent is off the tank it would be close to the tank and usually some kind of tiny foam filter to keep dirt out. Let us know what you find   

[Madmike]

Some of these have a choke that is sorta automatic and you have to hold them on at the carb with your finger to get them going.  I never seen a Briggs with a primer I thought only Tecumseh done that.  Maybe new fangled stuff.

In the past I have wired the safety bar up so that I have both hands to poke and prod with.  I know it isn't safe but so is pulling on the frigging thing for 6 hours and having a heart attack.

You can also unhook the safety shutdown to eliminate that as a problem - usually just a wire to pull off and it is open all the time - you may have to ground the wire to shut it off or pull the plug lead.  I guess this won't be a real problem though til you git 'er goin'.

Sounds like a carb problem though - you may want to get a can of WD40 and fuel it with that by spraying it in the carb throat in short bursts and see if you can keep it running for a bit.  If it runs  that way you can eliminate the ignition as a problem and at least know what part to curse at.

My family was all gypo loggers and we had lots of this junk around when I was a kid.  I think my cousin still holds the world record for the powersaw throw.

[BrettB]

Sounds like old fuel to me, probably gummed up the carb.  I have a small mowing business and do some work on small engines..............try this:   Make sure you empty old fuel and use fresh.  Add some Seafoam fuel treatment.  This is the best stuff ever.  Start the mower (tie the safety lever down so it will run without holding the handle).  As soon as it starts, go to the primer bulb and start pushing it when the motor starts to die.  Push it fast enough to keep the motor going.  You may have to push the bulb for some time until the motor starts to run smooth.  If the varnish in the carb isn't too bad, the Seafoam will clean out.   Just be careful...........remember the blade is spinning while you are doing this.  Good luck.

[R J]

Sounds like old fuel to me, probably gummed up the carb.  I have a small mowing business and do some work on small engines..............try this:   Make sure you empty old fuel and use fresh.  Add some Seafoam fuel treatment.  This is the best stuff ever.  Start the mower (tie the safety lever down so it will run without holding the handle).  As soon as it starts, go to the primer bulb and start pushing it when the motor starts to die.  Push it fast enough to keep the motor going.  You may have to push the bulb for some time until the motor starts to run smooth.  If the varnish in the carb isn't too bad, the Seafoam will clean out.   Just be careful...........remember the blade is spinning while you are doing this.  Good luck.

Stanley, do what this gentleman says and you should be good to go.......

DO YA HAVE AN AIR COMPRESSOR HANDY?   If so, take the idle screw out, count how many turns so you can get it back close, and blow air into that hole,  Gas will spray out of the carb, so stand back  a little bit.

I won't try to explain to ya how to get at the jets, so if that no workie, send me the carb and we will clean it up for ya...

RJ.

[Mr.BubblesVRCCDS0008]

Pinch the fuel line off and remove the carb. The jet in the bottom of the float bowl is clogged and needs to be cleaned. I use a tip cleaner for cutting torches to clear the junk in the jet. Spray some carb cleaner through all jets or vent hole in the carb. Check to make sure the float and needle are not dirty while your in there. The fuel we get now adays start to break down after about 6 weeks. IF you don't let it sit too long you should be alright for the rest of the grass cutting season.

[PharmBoy]

I have worked on a zillion B&S lawnmowers when I was young.  Made a living at it.  They used to have a one way valve in the gasoline pick up tube.  I'd bet that the one way valve is not working and the carb needs a new pick up tube.  Do not blow on the pick up tube with high pressure air. If you already have, it's ruined.  You can tell if it is working by gently sucking and blowing on it with your mouth.  It may not taste too good, but that is the only test that I know of...JTL

[V98]

A couple things to check, primer bulbs have been known to get a pinhole in them. When your fingers on it the hole is plugged, finger off, hole is open sucking air stopping fuel flow. Also check gasket between air filter box and carb. face. Again creates air leak that stops fuel flow. The last one had me pulling my hair out on a previous mower  . Good luck .

[Grandude]

Sounds like the fuel is restricted or else there's a vacuum leak in the bulb or diaphragm.

Since it has a primer bulb it probably doesn't have a choke or a bowl. The pick-up tube is probably gummed up so hopefully the seafoam will help.

It also probably has a diaphragm under a plate on the side of the carb held on by 3 or more screws. Or, it may be under the carb between the tank and carb. You should check it to see if it is ruptured or if there is trash under it. When you remove the diaphragm there will be a spring and a ring under the diaphragm so don't let them drop out and get lost.

You might want to turn the mixture screw all the way in and back out to where it is or maybe an extra 1/8 of a turn temporarily. It should be about 1 1/2 - 1 3/4 turns out.

[Mr.BubblesVRCCDS0008]

I work on these things all the time. If it runs by using the primer bulb most likely the main jet is plugged pull it and clean it and your in business. Comes from setting up too long and todays gasoline.

[Stanley Steamer]

I took the carb apart again...checked everything out, made sure that openings weren't clogged and etc....put it all back together...added some more seafoam, started it up and pushed the primer bulb until it would run(roughly) on it's own....after a few minutes, it cleared up and ran smooth, so like some of you guys posted, I'm sure it was just that the old gas had gummed up the jets after sitting all winter...I always use Stabil in my gas, but her Grandma probably never heard of the stuff.....I guess I'll add it to my list of year end chores......thanks for all the tips and advice guys...it helped a lot!!.....

[Scott from FL, now in Maine]

   Yeehaw! On the road again.......er on the lawn? Glad it's fixed 

[Mr.BubblesVRCCDS0008]

Now get out there and cut the grass.