lawnmower (petrol) engine – fix it or buy new?

Punky, you do know we’re going to need a video of the running engine once you’ve completed this might task 😛

i think i can do that, watch this space 🙂 at work from tomorrow for 5 days so will hopefully have it serviced and back together on wednesday.

EDIT: jus wundrin….. imgur for hosting photos, does it do vids too? or will i have to upload something to youtube say?

Yay, thanks to this awesome thread, I’ve just bit the bullet and had a play with mine, which I haven’t serviced at all for years – it’s now got a cleaned up spark plug, air filter and oil change. Runs lovely and a warm sense of satisfaction that it was easier than I thought and I didn’t break it! Cheers guys – you lot are always helpful for absolutely everything!!

Not sure if lawnmower’s are ripcord/ pullstart (I’m guessing they are) but don’t just go flalling away on the cord – SLOWLY pull and turn the engine over till at TDC (maximum resistance on the cord), let the cord go back in, slowly take the slack out then give it a good pull. Repeat until started.
Pull cords will thank you.

Couldn’t be bothered with my old mower any more so I bought a new one 🙂

Quite looking forward to it actually. New one is £600 instead of previous £1300 and before that £1800. So I only want it to last a year. New one is 35kg instead of 70kg. The only thing is it doesn’t have a BBC but I’ll get by with that.

🙂 Handy few features such as a fuel cap with a clutch so you can’t overtighten it, and a nice firm deck height adjust with only 5 positions.

New one is £600 instead of previous £1300 and before that £1800. So I only want it to last a year.

😯

Have they put fibreglass decks on a decent cutting lawnmower ?

We used to get through a 1300quid honda every 3 years due to Ali deck rot depsite washing the grass off the undersife regularly.

Also had an fibreglass etasia . It was a great mower if you were doing acres but was on wheels and was shit for doing gardens.

And we had a hayter for doing the walled garden and tennis courts.

Are you wearing a suitable shirt while working on the mower?

Is that a young James May?

Trail_rat – how about a Stiga ?

My mum has an acre and a half site, mix of paddock and lawn and a 2nd hand Stiga Park is excellent and seems very well made.

I’m no longer in that industry so don’t need one now but a quick look at stigas shows their self propelled unit has an alu steel deck same as the Honda’s.

The spring will be under your fridge. Sure someone hasn’t been using 2 stroke in it :p

The mower man is picking mine up this morning…. He’s basically going to do what you guys have suggested and sharpen/balance the blade for £110.

So well done to the gents who’ve save themselves a pretty penny.

Next time I’ll have a go myself (I hadn’t read this thread before arrange for the service)… but having only ever replaced the spark plug once in 9 years I reckon I can “afford” to let someone who really knows what they are doing give it some loving care to my Hayter Sprint 41.

But I am going to have a go at the strimmer…. It’s a 4 stoke so I’m guessing the principles are the same…. It’s ticking over ok but cuts out when you rev it up.

for the strimmer my first check would be a leaky fuel pipe especially if you have left it sitting with fuel in.

ironically the fuel pipes on most hand power tools – strimmer-hedge cutter-blower – chainsaw use a rubber pipe from the tank to the carb that degrades when fuels left in and goes brittle. picks up a hole – idles fine but when you stick it on throttle the sucking of fuel increases and it sucks in air through the hole.

Used to keep a roll of it in the van for when we got the symptoms you describe as it wasnt really practical for us to drain all tools after each use.

Thanks TR … that’ll be the first thing I check

update! failure….. 😥

its maybe even worse than before

couple of things i wasnt sure of tho, so alls not lost yet. firstly, the spark plug, havent got any feelers so just plopped it in as new and hoped for the best. not really sure its a spark plug problem tho.
secondly the springs. heres a couple of short vids of how ive got the springs. not sure theyre right tho. dont understand all that ‘governor spring’ sh1te and how it all works. i moved that little lever on the left a bit and got really high revs, so then moved it a bit to the left and got the low revs in the first vid, but it keeps dying on me still.

couple of times it died after a second or two anyway and wouldnt start again, then i left it and it started again next time, but still no good.

im sure i put the carb/gasket/diaphragm back together ok, and a new air filter rubbed in oil.

anyone care to hazard a guess? 😕

thanks

Sounds like it may be a fuel supply issue.

There’s no smoke so I’m presuming the compression is good and rings are not worn.

Shouldn’t you have a cable running from lever on ‘handlebar’ to the black lever attached to the spring in that last vid?

Shouldn’t you have a cable running from lever on ‘handlebar’ to the black lever attached to the spring in that last vid?

just been out to look, the handlebar cable goes to a little lever at the back of the engine which cuts it off when released, so that all looks fine and working as it should.

The springs look roughly right, but there’s something wrong as the linkages aren’t moving freely – the throttle (turny thing in the middle) should spring back fully clockwise, and it should take very little pressure on the linkage to close it (turn it anti-clockwise). Everything should move like a Swiss watch – it relies on the breeze from the cooling fan to close the throttle when the engine is up to speed and the springs to open it again under load. Be gentle with them! The carb is probably OK.

The link by your finger isn’t in its hole properly, and is probably binding:

Disconnect this and check that the arm near your finger (connected to the vane inside the cowling) is also moving very freely – may need a bit of a clean up. Provided it is, connect the linkage properly and check that the whole thing moves freely.

Have a look at this for inspiration:

Edit: You may need to take the carb off again to get that linkage in right – don’t force it!

The link by your finger isn’t in its hole properly, and is probably binding:

youre right, it didnt want to go in so i forced it a bit as it seemed the only way i could see that these springs connect.

Provided it is, connect the linkage properly and check that the whole thing moves freely.

thats just it, im not sure how it connects.

Have a look at this for inspiration:

thanks, found that with google and thats the exact video ive been looking at to try and see how they connect, freeze framing when it does a close up. still cant fathom it, cant see how else it can connect other than how ive done it, even tho it didnt want to…..

do you think these springs are they key to solving this issue?

EDIT: just watched the vid again and see what you mean about the doobery springing back clockwise, need to try and work out why mine isnt. done a close up of it again and looks the same as mine :-/

I think the springs are right – 99% sure that the binding is the issue. Look how freely the linkage moves in that video, and how it always snaps back to the same place.

I think you will need to take the carb off again to get that linkage hooked up correctly. It needs to be put in place as you fit the carb back on to the engine so that you have enough movement to wiggle everything into place. It’s not right as it is now.

yep, will do then, but one things baffling me. as you rightly say, the doobery springs back to the right every time until its pulled to the left and then springs back. but i cant see anything at all that would put any tension on it to keep it to the right. anything thats connected to it is to the left of it so youd imagine the opposite happening.

found another pic…..

I did the filter, carb, oil, plug thing to mine. It was still crap.

Sold it for £40 and bought a brand new Honda.

Never looked back.

I did the filter, carb, oil, plug thing to mine. It was still crap.

Sold it for £40 and bought a brand new Honda.

Never looked back.
i dont like things beating me, ill have another bash today. need to try and get tension on the doobery somehow to make it want to spring back to the right. if i cant, then i may have to go down the same route altho i probably wouldnt get £40 for a non-working mower 🙂

yeee ha, fixed it!!

I think the springs are right – 99% sure that the binding is the issue. Look how freely the linkage moves in that video, and how it always snaps back to the same place.

I think you will need to take the carb off again to get that linkage hooked up correctly. It needs to be put in place as you fit the carb back on to the engine so that you have enough movement to wiggle everything into place. It’s not right as it is now.
this was the key. took petrol tank/carb off again and checked the doobery, it sprang freely back clockwise. slowly put it all back together again all the time ensuring it kept springing back as per that video, then struck it up. far better 🙂
bit of a dip as it went through the rough/high stuff but i can live with that, probably to be expected. if we keep on top of it it wont get as long as that again anyway, this is all from last year.

thanks a lot for your help, much appreciated, this place is great.

Good stuff. Now for the most important thing; a picture of your lawn with fresh stripes! I love a stripey lawn. 🙂

Well done – and a nice view of the field!

Result! Well done 🙂

My lawn is available for extended trials…

ingwerfuchs – Member
Good stuff. Now for the most important thing; a picture of your lawn with fresh stripes! I love a stripey lawn.

POSTED 7 HOURS AGO #

For your personal pleasure

holy thread resurrection batman.

just asked the mods to re-open this but it says i can still post, so lets see……

lawnmower seems to have given up the ghost now, wont start at all.  its done a few cuts this year already but mrs ex-p cant start it at all, and now i cant either.

i’d go over all the above again and service it again but ive noticed that the squidgy priming jobbie spurts petrol out when pressed too, so not sure how much of a deal-breaker that is.

as with the OP 7 years ago 😱 mrs ex-p is desperate to buy another, whereas id like to keep it going forever, the ‘triggers broom’ of lawnmowers 😆

is it finally time to lay it to rest do you think?

cheers

Any trigger’s broom is a challenge to keep it going forever. You don’t just retire a trigger’s broom when a small part can be replaced or fixed.

Fix it!
Fix it!
Fix it!
Fix it!
Your wife is having a 7year lawnmower itch!

excellent, my wifes soooo chuffed to bits with your answers 😀

and that squidgy prime button that leaks doesnt mean death to the lawnmower then no?

and i just need to service as above all those years ago, assuming that the links still work of course?

thanks

I have just done mine.

Gasket and diaphram, springs and plug, primer bulb, fresh petrol and good as new.

Ebay for the kit, Youtube for the how to. Mines the 35 too.

Ebay for the kit, Youtube for the how to. Mines the 35 too.

would you mind linking me to the exact kit that you bought then please mate?

ta

Love this thread. I have the same engine in my mower! I’ve had it for 22 years now and never serviced it, other than giving the spark plug a clean every now and then. I’ve never even put oil in it! Oh, I did just put a new throttle cable on it last week.

It’s struggling a bit now and the plug gets choked sooner so I think I’m going to have to strip and service it. Will read this thread in full with great interest!

Great thread. Fix it. It’s the right thing to do for the planet, for your personal pride and satisfaction, for your bank balance, as an antidote to the ‘bin it and buy more shit’ culture etc. etc.

You know this. Your wife will come to know this. Everyone on STW is now rooting for  sadexpunk’s unkillable zombie mower. You simply can not let us down!

Seeing as we’ve lawnmover peeps in, I’m having a bit of trouble with mine….HOT starting.

Fires first time from cold, stop to empty the grass cutttings and it won’t restart. Have to wait 10mins before it’ll start again. Any ideas?

Last year it had plug, fuel filter and new carb. Emptied fuel over winter.

Mine’s a Webb WER400

Another saying fix it – I have a B&Q special but it has a B&S engine and had a couple of issues with it – once I smashed the throttle linkage against something and bent bits and snapped a return spring, but YouTube and a few new parts and it was right as rain. Then it started running roughly and leaking fuel as the carb gasket had split – replaced that and it was still doing it then I realised it was actually the carb base that had warped (it’s only plastic) so replaced that and all is fine. They really are easy to work on.

https://www.ebay.co.uk/itm/186353812114