Lawn mower problem

[coccinelle]

I have a petrol powered lawn mower (Briggs & Stratton engine). Last week when I used it it stalled and just stopped so thinking it needed petrol put that in and it did start up again after a while but wasn't the same. It went very slow and had a low sound to it anyway it finished the job. Yesterday, when I started it up it was the same so cleaned the spark plug which was rather dirty and cleaned the air filter. It kicked up well for a minute or two but then was the same. I changed the petrol as I was using last year's but that didn't make any difference. Anyway, after a poor performance but did manage to cut the grass it finally stopped and I can't get it to start again.
Anybody, have an idea what it could be? It has been working well all spring and summer it gets used 3 hours a week.

[TWR]

It apears you have muck in the system Coccinelle, replace the spark plug, take off the top of the carb & clean, check or replace your plug lead.

[coccinelle]

So you think it's the spark plug needing changing? Where will the muck be?

[Old_Geezer]

Just look for the brass.

I have a petrol strimmer I've given up trying to start. If you find the cause of your problem do let us know. I'll give it a go too.

[TWR]

When you take out the Plug, check the electrodes, has the plug the right size gap? for the cost of a plug I would replace, the new plug should be set to the right gap, but look if you have the manual to make sure.

[TWR]

OG, they are a pain in the @rse, from what I heard about them once stopped, it is a job to restart. but try a new plug for starts.

[scotman]

Sounds like gunge in the fuel line somewhere. Might be easy to find or you may have to dismantle and clean the lot.

[coccinelle]

Yes, it does sound as if something was slowing the procedure of the fuel getting to where it has to go and is now completely bunged up.
Unfortunately, I'm no mechanic so will have to rely on help to clean the carburator out.
OG; I gave up on those things years ago, too sentimental for my liking... 2 stroke engines are great for a season then it's over.

[Clanad]

You can find a can of carburetor cleaner at an automotive store. It's poured into the gasoline and does a fair job of cleaning the carb. Unless you're astute at repairing small engines, just accessing the carb could be a chore, much less taking it apart to clean it. There's lots of small pieces and you're likely to have a few left over and that's not a good thing. Try the cleaner first and if doesn't work seek out a small engine repair shop.

For O.Geezer... any information applicable to the lawn mower engine will be useless for helping you with the "strimmer" assuming it's a two stroke engine (most are). If you mix the fuel and oil together it's a two stroke and the science is entirely different with the exception of still lots of small pieces, none of which should be left over.
One quick suggestion though... near where you set a control for cold starting or even a little plastic bulb pump primer will be two tiny screws fairly close to one another. One of these sets the idle speed mixture whereas the other one sets the high speed mixture. Using a very small bladed screw driver, turn both all the way in (CW), pull the starter cord through a few times (to clean the carb) and then open both about 2 1/2 turns (CCW). Try to start it... if it runs, adjust one of the screws to get a smooth idle and the open the throttle and adjust the other to get a smooth high speed.
Be especially sure that you have used the right oil/gas ratio... most are 50:1 (gas to oil) but be sure to use your owner's manual recommendation...

[TWR]

Coccinell, its not as bad as what you may think " Honest" look for the fuel tank there should be at the most 2 bolts holding it in place, remove it & give it a thorough clean out, follow the fuel line to the carb & disconnect & blow through the pipe & as I have said also the carb, your problem should then be sorted.

[coccinelle]

Right TWR that's my mission for tomorrow.... give it a clean out with what? water? alcohol????? I suppose the fuel line is something which links the fuel tank to the carburator? which can be disconnected (how?) and blown through??
Sorry I'm coming over thick but I want to do this properly and I'm new to this game!

[The-HouseHusband]

Dont use water to clean out fuel lines or carb's as it will just cause more problems. Use white spirits or parraffin as these will evaporate.

Another problem could be the magneto is failing to create a strong enough electrical charge to give a decent spark at the plug. If this is the case it requires a specialist repair or a new lawn mower!

[TWR]

You can either used whats been said or petrol, just take your time & I thuink you will succeed & sort out your problem.

[TWR]

I should also said, there should either be clips that can be pulled off the fuel line or there will be Jubilee clips, if there is muck in the pipe use a straightened metal coat hanger with a bit of cloth & pull through the pipe, make sure that the pipe is fully cleaned, I would not start to dismantle the carb just take the top off that should be held in place by 4 / screws,use clean petrol to clean out, DO NOT SMOKE

[coccinelle]

The problem has been solved and my lawn mower is working again thanks to my friendly neighbour! He did a good clean of petrol tank, pipe, spark plug and carburator with me looking on to see what to do another time. Thank you for all your help as I understood what was what thanks to you.
Waiting until it cools down a bit to finish off the mowing.

[TWR]

Good, nice one, should the problem come again in years to come Coccinelle, take the pipe off fuel pipe off the tank & drain, leave for about 20 mins for the fuel to evaporate from the mower, recouple the pipe. petrol if left for an year would require changing as it can get water into it.

[coccinelle]

No, it's a 4 stroke engine. And though everything seemed fine after a few minutes the problem started up again. I managed to cut for an hour or so but it then stalled and wouldn't start up again. The neighbour's going to change oil and probably fix a new spark plug... don't you just hate it when tools don't work???

[RATTER15]

also worth removing the coil, clean contacts, check and adjust gap on replacement, I just had these exact problems on my Briggs and Stratton lawnmower.

[coccinelle]

What is the coil and 'adjusting gap on replacement? My neighbour's french so need to know what these are. Thanks for your help.

[Old_Geezer]

Ah yes, mine is 2 stroke. As is the strimmer. I'll try the suggestions maybe next weekend. Thanks.