Lawn mower will not start

[mudman]

Well it’s that time of year again

Lawn mower out of the shed and the damn thing will not start

An old Honda HR173, from what I’ve read they are pretty much bullet proof. Pull start petrol.

Third or forth pull and it fires, runs for five or six seconds then stops. Will not fire up again until it has had a long rest.

Straight to YouTube, I find a tutorial for this very model. Go out and buy a spray can of carburettor cleaner. Strip down and flush out carb and its components as instructed on the video

Empty old petrol from the tank and half fill again with fresh.

Reassemble.

Bloody thing does exactly the same, except fires up second or third pull this time but then again fades away after a few seconds.

Anybody able to offer any advice before it goes to the tip?

 

[biffo]

Clean air filter? Wash the sponge cover in petroleum to get rid of any oil and dry thoroughly before putting back.

 

[HonestJohn]

New fuel filter, air? ? Clogged likely. Always at end of season run it empty until it dies from exhaustion. Then half fill it with aspen

 

[mudman]

New fuel filter, air? ? Clogged likely. Always at end of season run it empty until it dies from exhaustion. Then half fill it with aspen

Mmm

Could be the fuel filter.

Not sure where it is. But I will find out and check it out.

When I took the bowl off the carb the dregs of petrol were quite dirty. Full of tiny bits, although carb itself looked quite clean and the jets were clean.

 

[Triggermortis]

A coating of varnish from the “old” petrol has formed on the Venturi in the carb, sometimes even carb clear don’t work.

 

[Tim.243]

Well it’s that time of year again

Lawn mower out of the shed and the damn thing will not start

An old Honda HR173, from what I’ve read they are pretty much bullet proof. Pull start petrol.

Third or forth pull and it fires, runs for five or six seconds then stops. Will not fire up again until it has had a long rest.

Straight to YouTube, I find a tutorial for this very model. Go out and buy a spray can of carburettor cleaner. Strip down and flush out carb and its components as instructed on the video

Empty old petrol from the tank and half fill again with fresh.

Reassemble.

Bloody thing does exactly the same, except fires up second or third pull this time but then again fades away after a few seconds.

Anybody able to offer any advice before it goes to the tip?

Not enough fuel as it then dies so main jet/s are tiny...you need to be able to blow through the jets and hold them up to a light.
A flow of clean fuel is your starting point as then the holes get smaller and smaller

 

[Taff]

Try running without air filter, if it runs it’s flooding, change old fuel ,clean air filter, give a blast of carb cleaner. If not resolved, Remove carb bowl clean and remove dirt and moisture, remove float needle and blow through with airline if possible.

 

[enfieldspares]

Try turning the tap on and off and then on again between the fuel line and the fuel tank if it has such. Not meant as a flippant remark but it may be that this has become clogged there so that some fuel is passing but not in enough amount?

 

[HonestJohn]

Once you get it working, remember to prep it well at the end of the season, i do this with all my machinery to ensure they’re starting and working spot on when you need them to the next spring

 

[Will the chippy]

I've had so many issues with petrol stuff these last 5 years, I've changed carbs cleaned this and that, new plugs and air filters. And 99 percent of the time it's crap fuel. Dad bought some new fuel for his quad, it was stale when he bought it. Changed it for new premium fuel and it was fine.
I'd by some more new fuel from a different garage, empty the old fuel out, If your mower has a a primer bulb use it more than you need 20 pumps plus, just to flush the system. Then it should start ok.
I use premium fuel and some fuel stabiliser now as I'm fed up with stale fuel. It'll go stale in less than 6 weeks now with the bio fuels.

 

[User00056]

I'd take the carburettor off completely, and put it into an ultrasound cleaner if you thave one?

 

[hendrix's rifle]

I'd take the carburettor off completely, and put it into an ultrasound cleaner if you thave one?

Id second this providing you strip ALL rubber seals away first otherwise it will eat them...

Get a carb cleaning kit for the jets, give em a good soak in carb cleaner and push a needle or similar through and check they're clear. Pull the spark plug + give it a clean and reassemble after checking fuel filter + air filter

 

[Alhamander]

Try balancing it at a 45* angle and then pulling it. Mine starts like that, leaning to the left (right wheels in the air) at around 45*. No idea why...

 

[KimE]

I still have two feet of snow

 

[Pedro]

Don't think anyone's mentioned the spark plug. Clean it, or maybe get a new one and check the gap is correct.

 

[long_range_rob]

I always run my petrol kit dry of fuel before storage. The modern E10 stuff is rubbish. In your case I’d empty the carb and fuel tank and refill with some decent petrol like V power or the 99 octane stuff.

 

[Tikkat1x]

Don't think anyone's mentioned the spark plug. Clean it, or maybe get a new one and check the gap is correct.

i was just thinking why has no one mentioned the sparkplug
i have an old honda izzy and i will pretty much guarantee you it will be the sparkplug

 

[NoIDeer]

Is the fuel filler cap/tank breather blocked? The fuel tank can drawn a partial vacuum and stop the engine.

 

[hendrix's rifle]

Don't think anyone's mentioned the spark plug. Clean it, or maybe get a new one and check the gap is correct.

#12

 

[marineboy]

Boil the carb in soapy water. Change the spark plug. Clean air filter look in tank for fuel filter. Change fuel