Ride on Mower, running rough (Briggs & Stratton)

[PersonalJester]

Hi there, hope some one can help.

My ride on mower has started rough running.

It's a CastelGarden, but the engine is Briggs & Stratton.

It starts fine but then starts missing (I think) that is what is happening.

I have a utube video here, as is best for anyone to hear what it is doing:
http://youtu.be/m4g3brLQNmE

Any hints would be much appreiated.

PJ

[PersonalJester]

Thought I had better let you know the engine model etc. before anyone asks!
Image attached.

[OscarIndia]

Sounds like dirt in the Carburetor.

[TVR keith]

That does sound like fuel starvation. Try removing the fuel pipe at the carb end to see if you have a good flow. If there isn't it could be a blocked fuel filter or even muck in the often very small outlet pipe on the tank.

Oh, and welcome to Pistonheads

[Timmy40]

TVR keith said:

That does sound like fuel starvation. Try removing the fuel pipe at the carb end to see if you have a good flow. If there isn't it could be a blocked fuel filter or even muck in the often very small outlet pipe on the tank.

Try taking the fuel filter off and giving it a vigorous blow to get any dirt through, a new filter is a cheap part anyway.

[Busa mav]

I would just put new plugs and a fuel filter in it.

Have a look at the air filter too , they get full of dirt so quickly.

[Kapenta]

All good replies so far. Bad fuel. Drain the bad fuel from fuel tank by popping the fuel line from the carburetor into a suitable disposal container. Undo the carburetor bowl nut, reminder and empty the bowl. Check it for muck and corrosion from the water which has been absorbed by the ethanol in the fuel. Replace carb bowl, ensuring that you don't pinch the rubber o-ring.

Try again and report back.

If this doesn't cure it, then you will need to service the carb and clean needle and seat.

[Timmy40]

Kapenta said:

All good replies so far. Bad fuel. Drain the bad fuel from fuel tank by popping the fuel line from the carburetor into a suitable disposal container. Undo the carburetor bowl nut, reminder and empty the bowl. Check it for muck and corrosion from the water which has been absorbed by the ethanol in the fuel. Replace carb bowl, ensuring that you don't pinch the rubber o-ring.

Try again and report back.

If this doesn't cure it, then you will need to service the carb and clean needle and seat.

I forgot the bit about the carb bowl, good point.

This thread has been handy, reminded me to service my Snapper so I gave it a new fuel filter, oil change and oil filter last night.

[guindilias]

Those engines are picky as anything about the valves being adjusted right, something to check after you've had a look at the fuel system?

[PersonalJester]

Thank you for all your replies.

We only just moved into the house and so having to spend a little time every now and then on this, as have hundreds of boxes to empty. So my apologies if I don't respond quickly!

Took air filter off, still same problem (put it back on).

I took fuel pipe from carb, lots fuel getting through filter. Emptied and refilled tank.

I have noticed something. There is a lever moving in sympathy with the engine going 'up and down'. It moves at same timing. It moves by itself, so is that the Governor?

Maybe someone can let me know. Image with arrow attached:


If that is the Governor then would that move because of the fault, or is it part of the fault?

Any responses, as ever, appreciated, I will try and reply ASAP.

[DrDoofenshmirtz]

Similar thing happen to my cylinder mower - to fix, I removed the main jet and the emulsion tube (easily accessible from the top of the carb in my case). At the bottom of the emulsion tube are some tiny holes. These were blocked. To unblock them I had to use a tiny sewing needle.
|http://thumbsnap.com/mpQhqe0O[/url]

On another rotary mower (I have a lot of mowers!) with the same issue - it was due to a split diaphragm in the carb. £2.50 for a replacement part on eBay fixed that one perfectly.[url]


ETA - yes, that is the governor - it acts off the air flow though the engine to keep the revs stable.

[Mark Benson]

DrDoofenshmirtz said:

On another rotary mower (I have a lot of mowers!) with the same issue - it was due to a split diaphragm in the carb. £2.50 for a replacement part on eBay fixed that one perfectly.[url]

My petrol Briggs & Stratton sounded just like yours in the clip and the above fixed it. Easy to do, too (plenty of videos on Youtube to follow).

[Kapenta]

Mark Benson said:

My petrol Briggs & Stratton sounded just like yours in the clip and the above fixed it. Easy to do, too (plenty of videos on Youtube to follow).

He doesn't have a diaphragm pump carburetor. It's a gravity feed bowl type (Walbro).

https://www.youtube.com/watch?v=J6ZPp3wDf0M

Edited by Philemon on Thursday 28th May 16:45

[Kapenta]

Mark Benson said:

My petrol Briggs & Stratton sounded just like yours in the clip and the above fixed it. Easy to do, too (plenty of videos on Youtube to follow).

He doesn't have a diaphragm pump carburetor. It's a gravity feed bowl type (Walbro).

https://www.youtube.com/watch?v=J6ZPp3wDf0M

https://www.youtube.com/watch?v=ioGIQIVLukw

Edited by Philemon on Thursday 28th May 16:46

[Timmy40]

Kapenta said:

Mark Benson said:

My petrol Briggs & Stratton sounded just like yours in the clip and the above fixed it. Easy to do, too (plenty of videos on Youtube to follow).

He doesn't have a diaphragm pump carburetor. It's a gravity feed bowl type (Walbro).

That must be what I have, there's a little tit shaped bulb under the housing that you undo a nut to take off. Sometimes I undo it and wash it out to give it a clean with some petrol.

[PersonalJester]

Sorry for re-animating this thread but realised I didn't report back after fixing the problem.

I took the carb to pieces! A pretty simple affair, not that hard.

I dismantled it. Cleaned as best I can all parts. I did find (as others suggested) there was 'crud' in the bottom fuel bowl.

Put back together. It has worked correctly since.

Thank you for all your help.