[daveinmanc]

hello folks  

bit of a vague one on my part here cos this is the other halfs mower so i'm not familiar with it at all, i'm sure there will be someone on here that knows the in's n out's of them though so here goes  . . . . . .


i have the task of attempting to fix it, symptoms are, it won't start  

it's a mountfield quattro, it has a briggs and stratton SP 470 motor in it, it has fuel, oil and a spark from the plug and sounds like it will go but it's just not making the ' i'll go in a second ' noises !

firstly, as i'm not familiar i'm presuming i keep the red left hand handle lever pulled in (safety cut out) prime it 5 times as it says then pull the cord?

i've tried it both ways, with the other handle 'in' but  no joy  . . . .  

there appears to be a fuel leak coming from the front too but that may be flooding???

like i say, it's not my machine but i am willing to try and strip it down and have a go, the blade also keeps falling off when you attempt to start. don't know if this has any bearing on it? there's clearly a bit missing that locks the blade in place but it was one of those -' lent it out to someone aand it came back like this'  scenario's  . . . . . . . . .  :shock:


all answers appreciated, thank you people

[Zak the Rabbit]

ive got a cheap mountfield, could be the same one,

have you cleaned the air filter? mine was chock full of oil grime! Clean it in a bucket with abit of petrol (put some marigolds on if yer not 'nails' like i am ), sqeeze it out, sqeeze a bit of fresh engine oil into it, and refit.

also, check the cables are tight, my cable for the deadman lever was slack and stopped it working, they can be adjusted fairly easily. Another thing is to take up the slack on the starter cord before giving it a good pull, the ammount of slack on mine means if i dont i expend too much of the pull energy on the slack and theres not enough to turn the magnetos over (blimey, did i just say magnetos? i guess thats how the spark is formed!)

[Zak the Rabbit]

hello folks  

firstly, as i'm not familiar i'm presuming i keep the red left hand handle lever pulled in (safety cut out) prime it 5 times as it says then pull the cord?

make sure you keep the lever pulled! prime it first, then take up the lever and start, the lever needs to be in at all times. (im thinking you know this, but just thought i would point it out )

[daveinmanc]

cheers zak , the filter did look crappy and i thought it'd need a clean but didn't at the time as i wasn't sure if it was that bad it'd stop it from starting.

i trapped the lever down with a pair of latex gloves tied round as it happens
 lol !  

i tried a start with the filter off too and you could see fuel coming through when it was primed but didn't start still, take it they will with the filter off or is that too much air

[jack russell]

not sure if i miss read this but i would get the blade fixed first before trying to start it you don't want that flying off once its started

just a thought is there not a switch where the blade is attached so that the engine knows it is safe to start :shock:  if you get me  :roll:

[Gwiz]

On a lot of these small engines, the blade also acts as a kind of flywheel to help smooth out the power stoke from the engine.
result? no blade, or blade very loose, engine can be a right pain to start.
I'm not very familiar with the very new mountfields, but it sounds like a standard briggs engine.
If you follow the cable down from the dead mans handle, it will normally end somewhere on the side of the engine. When you pull the handle in, it pulls back a lever that frees a brake shoe, or sometimes a band, that acts against the flywheel. this mechnism stops the engine a bit quicker than wiothout it. it should also act on a small switch in the same area.
I often find that the switch isn't turning working as it should, and needs a gentle adjustment with a pair of pliers.
have a look at this first, but please tighten that blade up for safetys sake!!!!!!

[daveinmanc]

cheers chaps  

 i wasn't going to attempt to use it without the blade secured of course  . . . .

that was going to be dealt with once i'd established the engine would turn over, there's a mower shop on way to the other halfs so i'll stop in there wednesday and get the missing blade securing bit if i can.

i'll check out that cable as i'm sure its probably going to turn out to be summat and nothing, it worked perfectly well before the ' loan out ' i'm told so i'll go through all the advice you've given me here and see how i go.

thanks for all the replies and if there's any more suggestions i'm happy to take them all on board

cheers ! dave

 

[Bigbadfrankie]

burn it at dawn :?

[Gwiz]

burn it at dawn :?

   

[daveinmanc]

do i detect a hint of lawnmower snobbery here lol  :shock:

[Gwiz]

do i detect a hint of lawnmower snobbery here lol  :shock:

Heavens no. But if you can't get it going, it could be the most satisfying answer to the problem

[daveinmanc]

ok chaps still no joy  :cry:

have tried the above tips and although i get the occasional tempting ' cough ' where it sounds like its trying to start, it still won't go the whole hog. . . . . .

i've had the dead man switch fully open and its been inspected and cleaned and  it's not sticking, the air filters cleaned, there's loads of fuel in. there's oil - i have a spark  . . . . .  so what next

i have noticed when you pull back on the starter cord it will sound like its going to go when its been primed but on the pulls after it sounds less willing?

you also get a right kick back of it sometimes and it yanks the puller out of your hand that fast i'm surprised i aint broken a finger in the process lol  :shock:  erm, is that normal

so the question is, apart from the above, what do i tinker with next ?
 :roll:

edit: am thinking this may be a fuel thing rather than a fault finding mission? how do i check the fuel is getting through from the tank to the carb etc

[Gwiz]

right, this is what I reckon could be wrong.
If the blade was loose, it's more than a little possible that the last person to use it hit something rather nasty.
To check to see if this was the case, have a look at the blade. for safetys sake, take the spark plug out first, then tip the mower backwards so that the spark plug is pointing up towards the sky ( if you do it this way, you wont tip the oil where it shouldn't go.
Does the blade have a big nick in it, or a dent on the cutting edge? it should be straight, and uniform without a wavy edge.
If it does look like its bashed something, it's a fair bet that the aluminium flywheeel key has sheared in two. this will put out the timing, making it all but impossible to get going.
From what you describe, this sounds the most likely problem, either that or water in the petrol, which would also give the same symtoms of a cough now and again, but other than that, a steadfast refusal to fire into life.
if it's a briggs engine, there will be four screws that hold the engine casing on, you won't need to take the flywheel off unless you camn see that the key is snapped. you will be able to see the key-ways very clearly, if they aren't inline, then its been snapped, I hope thats the cause, it's simple to fit a new one, and will cost no more than a pound.
all the best
graham
if you need more detailed instructions, give me a pm with your phone number and a time when it would be ok to phone, and I will guide you through it.

[daveinmanc]

hello graham, yes the blade must have hit something as the two lugs that the blade sits into have sheared off and i've ordered a new one.

thought the motor would maybe start without the blade on so thats why i've been trying, just to make sure it'll kick into life first but if the blade acts to help with the start then i'll fix the blade problem first before attempting again.

had the carb off and it all looks clear and no gauzes blocked or anything, what i do need to know is how the two springs are meant to be arranged if anyone knows? they seem to control a white plastic ' fan 'type thing for want of a better expression ? lol ? this opens and closes but i cant see where it's meant to attach to, but i know it opens and closes the carb for air to the exhaust, just cant think of the proper terminoligy, been ages since i've fiddled with an engine and i've no idea what the last person that touched this did to it apart  from knacker it up lol.  :x

maybe ill do some pic's and post them so you can see what i mean . . . . .

cheers

dave

[Gwiz]

pics are good, they say a thousand words.
I think the thing you are describing is the butterfly fly valve (throttle)
there is normally a link and spring that goes back to the guvenor arm, and one which links to the throttle lever mechanism.
Did you check the flywheel key? beleave me, it's worth doing if the blade has hit something, as it is designed to sheer in two ( putting the timing out and stalling the motor, before damage occurs -HO, HO! )

Once you have put a piccy up, I'll see if I have a diagram I can photocopy for you, you never know your luck ( I do though, it's usually bad )