briggs and stratton engine

aidanki

hi all,

had a phonecall from my cousin this evening about her lawnmower.

It starts runs for 20secs and then cuts out.

the mower is only a year old and she uses it for cutting a lawn the size of a decent sitting room.

it has a 5hp Briggs and Stratton engine with the pump up button for starting (by pump up button I mean you have to press this red button 3times to prime it before starting. button is located between airfilter and engine)

like i say you prime it pull the cord to start it, it runs for 20secs then cuts out

airfilter is clear spark plug is good

fuel used was always from one of those safe plastic containers the one you buy so you won't dirty the fuel

any ideas?

colm_mcm

Choke not set properly or stale fuel would be my guess

puzzle factory

sounds like theres dirt in the carb, with a fuel pump, primer your probably pushing fuel through the dirt, with gravity flow like yours it wont go, check the fuel filter, or if its not that check the bowel in the bottom of the carb.

puzzle factory

oh and those
"safe plastic containers"
make no odds to clean fuel, you should run diesel through a white cloth, pure gunk gets filtered out of it.

aidanki

colm_mcm wrote: »

Choke not set properly or stale fuel would be my guess

automatic choke and tried it on fresh fuel same story

aidanki

puzzle factory wrote: »

sounds like theres dirt in the carb, with a fuel pump, primer your probably pushing fuel through the dirt, with gravity flow like yours it wont go, check the fuel filter, or if its not that check the bowel in the bottom of the carb.

might investigate the dirty fuel filter

meercat

there is a small filter on the fuel inlet
its in the petrol tank though
you will have to take the tank off to get at it
possibly a job for your local machine expert

jimmyw

Give it more primes than 3, I find its not enough.Possibly at least 5.Also as was mentioned, could be a blocked filter that's attached to the carb and going into the tank.You cant really clean it, its better to actually change it as its only press fitted into the carb body.But the carb will have to come off.

Make sure the fuel is actually up in the tank because although you can see fuel in the tank, it might not be covering the filter which is where the fuel is drawn from.Some modern lawnmower carbs don't have a choke flap (valve) so it really uses the primer for this.The primer itself could be split or perished too.

Another possibility could be a worn diaphragm if its got this type of carb which the checks above apply to.Cant do them checks if its got a fuel bowl on the bottom of it.A person that dabbles in cars and such should be able to do this, but if your not confident to do it, then go along to a workshop.

bijapos

aidanki wrote: »

.............................................the mower is only a year old and she uses it for cutting a lawn the size of a decent sitting room..................

Gardening tip: for such a small lawn (even though you probably exaggerated a bit;) ) just get a mechanical push mower and save money, hassle and grief over the next couple of decades.

unkel

What forum is this again?

ozmo

aidanki wrote: »

hi all,

it has a 5hp Briggs and Stratton engine with the pump up button for starting (by pump up button I mean you have to press this red button 3times to prime it before starting. button is located between airfilter and engine)

like i say you prime it pull the cord to start it, it runs for 20secs then cuts out

any ideas?

If its a two stroke engine and you haven't put in the two stroke oil - it could behave like this.

beanie10

Is there smoke coming out of exhaust when it does start?
Check engine oil, does there appear to be petrol in it?

E39MSport

unkel wrote: »

What forum is this again?

Sweet. I'm posting up a pic of my ride-on tomorrow (so many jokes, so little time ..... ) and my strimmer. ICE all the way

you should see my food blender

carbon nanotube

b&s made some legend of lawnmowers, we had a castlegarden one, think that's the model.

going back 30 years. my dad bless him must have practically have it opened up each other day to keep it running, must have lasted up about 20 years that mower.

near the end of its days it sounded like a 200bhp tractor on full throttle tho...:p

jimmyw

carbon nanotube wrote: »

b&s made some legend of lawnmowers, we had a castlegarden one, think that's the model.

going back 30 years. my dad bless him must have practically have it opened up each other day to keep it running, must have lasted up about 20 years that mower.

near the end of its days it sounded like a 200bhp tractor on full throttle tho...:p

Christ, dont remind me.We used to have a green hayterette mower with I think an 8 cubic inch cc B and S engine that the rings were changed in with no special tools,(hammer mainly:p) and a load of other things,points adjusting, breather valve gone which resulted in oil leaking from it.It was a constance job to keep her running (literally:eek:).Wheels all over the place.But I did learn my (DIY) trade on it though.

I think she could have been made in the 70s.This was in the eighties now.

corktina

unkel wrote: »

What forum is this again?

yours, Boss.....

Welease

If it is a 2 stroke (as mentioned earlier), my guess would be the wrong mix of oil and fuel in the tank.

2 stroke

ozmo wrote: »

If its a two stroke engine and you haven't put in the two stroke oil - it could behave like this.

Welease wrote: »

If it is a 2 stroke (as mentioned earlier), my guess would be the wrong mix of oil and fuel in the tank.

Did somebody call me? I think most posters on this forum will know that b&s made mostly 4 stroke engines.
Will the engine restart immediatly if you pump the button just after it cuts out, if it doesn't, I'd try changing the spark plug. I've seen plugs that only failed when hot. Also is there engine oil in it, a small engine could be tightening up and releasing again when cold

Paddy001

Its most definitely 4 stroke, if it isn't they'd know before now. Check there is a healthy spark from the plug and that the lead fits it ok and try a fresh tank of fuel, it sounds like a fuel problem if its able to start but not stay going

vectra

Could be a faulty Diaphragm in the carb.

corktina

don't forget to post up some pics, we love pics of our peeps rides.

Indricotherium

jimmyw wrote: »

Give it more primes than 3, I find its not enough.Possibly at least 5.Also as was mentioned, could be a blocked filter that's attached to the carb and going into the tank.You cant really clean it, its better to actually change it as its only press fitted into the carb body.But the carb will have to come off.

Make sure the fuel is actually up in the tank because although you can see fuel in the tank, it might not be covering the filter which is where the fuel is drawn from.Some modern lawnmower carbs don't have a choke flap (valve) so it really uses the primer for this.The primer itself could be split or perished too.

Another possibility could be a worn diaphragm if its got this type of carb which the checks above apply to.Cant do them checks if its got a fuel bowl on the bottom of it.A person that dabbles in cars and such should be able to do this, but if your not confident to do it, then go along to a workshop.

+ 1 to it needing more than 3!

aidanki

Welease wrote: »

If it is a 2 stroke (as mentioned earlier), my guess would be the wrong mix of oil and fuel in the tank.

4 stroke ordinary lawnmower engine

corktina

ordinary or is there something else about them....?

http://www.youtube.com/watch?v=WAynvmMoWaA