Lawn mower running rich

[Oaktech]

If its got a Auto-Throttle, does that mean it also has an auto-choke? perhaps the choke is jammed open, allowing too much cack into the combustion chamber....which would be why your spark plug is coming out covered in carbon dust.
The choke in theory should only be open for a cold start for the first 2-3 mins until the engine warms up...which doesn't take long on a small mower engine.

My Honda had an auto choke and it was a pain in the a***, had to clean the spark plug really regularly - like once every 2-3 cuts

Briggs and stratton, auto choke... Come along now, you over estimate the complexities of american engineering!

It's got a primer bulb, you prime it, then you just keep turning it over till it starts!

[Oaktech]

Or a goat - have some goats milk as well if you like that sort of thing :P

sheep are stupid and expensive in vet bills, goats are intelligent and escape a lot... What you need is alpacas.

[HaleStorm]

Ah yes...fine american engineering....and the "just keep trying until it starts of you dislocate your shoulder" approch

[pcstru]

sheep are stupid

Very.

and expensive in vet bills

Not if you have a suitably sized chest freezer.

[HaleStorm]

I find with Sheep...if shot of Streptopem doesn't fix it then its beyond repair.
Goats are much easier to fix because they are more resilient than moron sheep

[Sirbendy]

Ah yes...fine american engineering....and the "just keep trying until it starts of you dislocate your shoulder" approch

or it kicks back and breaks your wrist/fingers/pulls out over.

[woodham]

get the carb diaphram replaced they are about a fiver a set from any repair shop or of ebay.

it also acts as the fuel pump. they go "baggy" over time and stop working

whatever you do only do one thing at a time and then check it, the govenor springs always look very slack dont worry about them.

[laserblazer]

I just cleaned the plug, sprayed WD40 on all the moving parts around the carb plus a big squirt down the air intake. I turned it over a few times with the plug out and then poured petrol down the air intake and turned it over again a few times. Put the plug back in and it fired first time. A bit of smelly smoke, from the WD40 residue I suspect, and I've cut front and back lawns. It still hunts a bit, so I may strip it right down in the summer hols.

[mac_shinobi]

... What you need is alpacas.

Don't they spit ??

[woodham]

the hunting will be down to the carb diaphrams , just get some off ebay and change them

if you can use a screwdriver then it's a five minuite job and will make the world of difference.

be careful poreing petrol into the cylinder as it will wash the oil of the bore and fill the oil with petrol and thats not good for the insides of an engine.

[Oaktech]

Don't they spit ??

Nope, thats Llamas!

be careful poreing petrol into the cylinder as it will wash the oil of the bore and fill the oil with petrol and thats not good for the insides of an engine.

Thats fair enough, but you will notice that I explicitly said that I changed the oil afterwards - thats why!

[LMP]

Running rich..yes..mine...classic B&S 2.5 hp
Clean. New spark plug. new diaphragm. This has increased progressively.
I remove air cleaner...block choke open with clothes pin. Same....it runs OK no load..but as soon as throttle opens, it begins sputtering black smoke.
Have removed, cleaned, "adjusted" carb several times to no joy....
All above recommendations executed to no avail.
Will report findings...