Grrr - Won't Start!

[Grip Fast]

I ticked Duxford Imperial War Museum off the to-do list yesterday, and had a nice run out there and back on the bike, so was well pleased with the weekend thus far. In order to keep the work-life balance correct, I decided to mow the lawn this afternoon.

But I can't get the mower to run (the title is a little misleading in mower ways than one - the pun was also essential). Once I tickle the carb, it starts and runs for about two seconds then dies. It's fresh fuel and it ran ok last weekend. I stripped the fuel lines and made sure there is no blockage. My trousers can vouch for there being plenty fuel getting through to the carb now. The air filter is clean and it has the same problem if I remove the air filter. Clearly there is a spark or it wouldn't fire at all. It seems like fuel starvation to me, but I'm baffled as to where.

I'm quite good a purely mechanical things, but when it comes to the internal combustion engine not running, I'm out of my depth.

The grass gets to grow for another week and my work-life balance doesn't feel quite right in spite of an afternoon's dedicated but essentially wasted effort.

[Gromit]

Our mower did this last summer - it was the carb diaphragm. Ended up getting a whole new carb (only 16 quid though and comes with a new diaphragm anyway) and all is well now. It surges for 20 secs or so on first starting but soon settles down and runs smooth as you like.

[Grip Fast]

Thanks Gromit. I'll take the carb off again and check the diaphragm, see if that looks suspect.

Cheers.

[Archie]

Maybe I'm missing something ( brain ) but a carb with a tickler will have a float not a diaphragm/pump?

When mine did this a new plug sorted it out.

[Grip Fast]

Just testing Archie.

Took carb off and stripped it right down - no sign of a diaphragm, but the float looks fine. No muck, blockages etc. it's all good. So maybe it's the plug, as you say.

I'm only glad it's the lawn mower and not the bike (touch wood).

[Gromit]

Depends on the motor - our Briggs & Stratton mower engine's carb sits on a very thin rubber diaphragm which contains a pair of flap valves between it and the fuel tank.

[dave the german]

Is it a Honda?

[Boxered]

I had that problem too, Briggs and scrap'em engine, new plug sorted mine out too.

Steve

[boxerscott]

Briggs and Stratton are brilliant little engines. They do lots of variants. generally speaking on grass cutters its the L head and if its a rotary it will have a vertical crank. The ones fitted with a rubber diaphragm and a cardboard gasket also have the pulsa prime squidgy thingy that you press three times to initially put some fuel into the carb. The pick up tube can also block as can the screen filter. It is also advisable to check governor spring and governor idle spring. Saying that I do not think this information is much use cos sounds like you have a gravity fed fuel system ie carb below fuel tank. What model is it?

Think we should have a gardeners corner, I`ve bin slaving all weekend and all the bikes passing by on the a68 below me make me wonder if bikers have gardens

[Grip Fast]

Thanks for all the feedback. Bad light stopped play yesterday without success. I'll need to have another go later this week. I can't get away from the feeling that is is a fuel problem.

The mower is made by Wolf but I don't know without looking if they make the engine. I haven't much cared until it didn't work.

My last one did have a Briggs and Stratton engine, which was still good but the bodywork rotted through.

Thanks again.

[ianbcr]

[quote="Grip Fast"]
My last one did have a Briggs and Stratton engine, which was still good but the bodywork rotted through.

Thanks again.[/quote]


Go-cart Go-cart.

[oyster]

Wolf and many others are merely re-badged standard mowers. Most rotary mowers are now based on the tough old Briggs Stratton engine, some are power drive with larger engines. Lot of poor copies of that engine these days. Three classic problems; 1. dead fuel/water in fuel/blocked fuelway in carb; 2. stretched or perforated diaphragm, damaged primer bulb; 3. spark plug.
The sneakiest is the plug; works fine while it is cold, when it warms up, it looses the seal between the ceramic and steel body.
After mowing, pull off the plug cap, lift mower onto one side and scrape out congealed grass. This extends the life of the mower body. This action must be carried out rapidly to limit loss of oil or fuel. Further service actions are also recommended to generally extend the life of the mower. I have seen one over twenty years old in regular use.

[dave the german]

Don't use it - find something more intereesting to do - will last forever then

[Al]

Better still let the gardener deal with it


Al.

[Grip Fast]

Better still let the gardener deal with it

Al.

But I am the gardener!

Not using it sounds like a good plan, Dave. I like that option.