Ride on mower running horrible!

[PersonalJester]

My CastelGarden ride on has started running rough.

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

I have a utube video which gives the sound it is making, far better than me describing it!
http://youtu.be/m4g3brLQNmE

The engine is;


Any hints would be much appreiated.

PJ

 

[ILENGINE]

Sounds like it is surging to me. Need to remove and clean the carb to start. the noise may be related to the up and down running of the engine. something you can try. With it running try adding a little bit of choke at a time and see if it will level out.

 

[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).

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.

 

[SeniorCitizen]

Your engine has a constant speed governor to regulate RPM at the speed you choose by adjusting the throttle lever and that lever movement is the gov. attempting to do its job. A lack of fuel often causes this ( BUT NOT ALWAYS ) so clean or have the carburetor internal passages cleaned.

 

[Grassbandit]

Sounds like fuel system needs a cleaning as the other guys already told you.
I'd take the opportunity to replace the fuel lines and filter just to be sure.
I watched the video, did you shut stop the engine yourself of did it stop on its own?

 

[PersonalJester]

Thank you for your posts.

Right, found some time to re-read your posts, grab the spanners and have a go!

Started by confirming there is plenty of fuel entering the carb.

Started dismantling the carb. Took air filter and filter holder off.

So looks like this:


At which point I fired her up to see if fault persisted. At which point she ran a lot better!

I couldn't understand what difference it made. So reassembled and tried again and still works OK.

I know it would be best at some point to clean out carb properly but would like to get the field cut first, as the grass jus keeps a growing!

At hi revs she sounds OK. At lo revs she does do 'something'.

This is a Hi revs video:
https://www.youtube.com/watch?v=RJemiLKWm3k

This is a lo revs video:
https://www.youtube.com/watch?v=htbAhu2OtJY

In the lo revs video, look at what happens about 3secs in. You can see it again later in the video, is zoomed in. Is this normal?

Seems like a lot of fuel is suddenly spurted out and the engine sound changes a little.

Let me know your thoughts, thanks in advance.