Anyone know anything about lawnmowers?

[slewthy]

Seems that everywhere I look at the moment, I find things that need repair/replacing/renewing

Latest thing is my lawnmower.

Its a rotary, self propelled one with a roller at the back for stripes. I dont know, its maybe a 22inch cut.

I've had it a while - its about 8 yrs old, but since its a Honda, that shouldnt be an issue.

So, symptoms are as follows.

Engine starts everytime. Idles and revs nicely. Doesnt stutter.

It will drive the rear roller along but then cuts out after 6 meters or so.

Engaging the blades results in the same.

It did this last season, and the one before IIRC but could be coaxed along and after about 10 stalls, would cut the entire lawn, no issues. Not so this season - Cant manage a stripe.

I have the Haynes Lawnmower book and its got this engine, so I've checked and cleaned the plug and set the gap. I've drained and replaced the oil and petrol. Ive stripped the drive train and clutch and cleared out a whole heap of stuff that should have solved the problem but it hasnt. I've had the carb apart and made sure all the air and fuel ways are clear.

I'm REALLY frustrated - I dont want to be doing this. The car is one thing but this is just a mower and I'm not having fun!

So, here are the questions.

1. Anyone got a clue?

2. What might be a reasonable price to pay an professional to fix it.

3. Should I just buy another. Bear in mind that a like for like replacement is upwards of £800!!!!!!!!!!!!

Just tell me what to do. I'm alittle cheesed off. (see other post to come later in this section to explain)

[freshcut]

A couple of questions; Does it immediately start up again after stalling or do you need to pull the starter rope a few times to get it started up again? Also, do you know if this unit has a pulse type fuel pump or if it's gravity fed? It ALMOST sounds like a fuel starvation issue under load which is when consumption is highest. The direction I'm going in is that there is enough fuel in the float bowl to run a few feet (meters in this case), but sounds that the fuel flow isn't able to keep up with fuel demand. If it's a pulse type pump it'll likely have 3 hoses, one from the tank, one to the carb, and one to the engine crankcase. It uses positive crankcase pressure to drive the pump. which is directly related to my question about how much you easily it starts after stalling. If it's multiple times, I'd suspect the pump which is pretty reasonable at just about $15usd the last time I replaced one.

[slewthy]

Well, to answer your questions,

It doesnt start immediately after the stall - it either takes several pulls or if I wait a minute or so, it will start again first time. Hmm - filling the bowl gradually?

Its a gravity feed.

I've checked to tank for debris - none.

Today, as soon as I applied load in the form of blade engagement, the engine stopped. Previously, that didnt stop it, but I have had it all apart - engine off, carb and exhaust system off. Panic moment and quickly refitted them. All the throttle, choke, governor and other springs etc match the workshop book but I might have inadvertently changed the throttle by reattaching the throttle cable slightly differently.

Oh, I should own up to 'fiddling' with the mixture and choke settings last year, but didnt seem to make any difference to anything. Could be an issue though

[freshcut]

Does your manual include any information on the adjustment screw set points? generally on small engines with a single adjustment screw, full closed, then back out 1.5 turns. Unfortunately my brain isn't working well enough right now to remember for mixture, but idle should be the one with a spring and that too should be 1.5 turns from full closed. If you feel confident enough to diassemble the carb, I'd certainly pull the float bowl off and check the needle valve to ensure its not sticking closed/open. Also, there should be a small jet in the bowl assembly attached to a stem and that jet must be clear as I believe it's part of the enrichment circuit that provides the extra fuel under load. If you get so far as to disassemble the carb, I'd just suggest spraying out any port/passage you can access to ensure nothing is plugged by a stray bit of dirt, grass or any other debris.

[slewthy]

Yep - I havnt got so far as to dismantle the carb yet. I'll get some carb cleaner and find the main jet.

[ramjet]

Simon,

I have a reel mower with a Honda engine and even though you have said you have changed the oil, have you checked the oil level switch? This caught me out several times when I first got the mower. It may be faulty and telling the ignition circuit under load that there is not enough oil and hance cutting the engine. May not be it, but easy to check with a multimeter.

Michael.

[theelanman]

I have a lotus......

what is a lawn mower????

Edited April 14, 2010 by theelanman

[stevem]

I had a similar problem last year with 2 machines, a lawnmower and a blower/vac. Both turned out to be a clogged up spark arrester, which is bascially just a bit of metal gauze that stops sparks from coming out of the exhaust and setting fire to dry grass. They are fitted to all garden machines here in oz, not sure about anywhere else - but worth a look. I was amazed at the difference cleaning teh gauze made.

good luck.

[IanQ]

Bet it is the first time you tried to use it this year and it is last year's petrol....drain it out, clean the tank and remove the waxy debris stuff in the float chamber on the carb. Clean and gap the plug. Put in fresh fuel and try it then.

[simonb]

Fuel pump - most likely part of the carb assembly

No Honda horticultural dealers near you?

[hilly]

A bit off topic and not much help but you should get one of THESE!!!!!!

I have got one and it is ace, but then I am a bit of a gadget freak.........................

Not mine, but you get the idea from this video.

Hilly

Edited April 15, 2010 by hilly

[Bibs]

[hilly]

But that hasn't got a blade guard, it would never get a CE mark to be able to sell it.................

[slewthy]

Bugger. I knew I shouldn't have posted this topic....

OK, OK you are all REALLY funny. But my grass ain't getting any shorter from laughin'.

I'll look at all those suggestions - cant see any fancy electronics to check nor any spark arrestor. Gunk in the bowl and crap in the carb are easy and worth checking.

Unfortunately, my local Honda dealer shut and they built houses there. Rubbish lawns too.

[IanQ]

If you need bits there is a Honda dealer in the next but one village to me. I am willing to pick up any bits you may need if they have them tomorrow and bring them to Malvern or post if you aren't going to the show but you will need to be quick.

[molemot]

RoboMower? To judge from the video, a remarkably stupid box of tricks...it seems to do mowing along the lines of giving an infinite number of monkeys a typewriter apiece and finally they will come up with all the works of Shakespeare...!! Poor little thing just stumbles about, lost. Felt quite sorry for it...needs some decent sensors and software, GPS chips are cheap these days, and then you could get a proper stripey lawn...

Here at Mole End Cottage I've done the annual blacksmithery on the mower blade, fitted a new tension spring to the cutter head drive, and amused myself by howling around the grass at about 15mph on my ancient 7.5hp ride on Mountfield...cost me £100 about 10 years ago, and it's done valiant service since!!

[slewthy]

Thanks Ian, I'm not going to Malvern unfortunately. If I need parts, I'll let you know.Many thanks!

[freshcut]

Simon, any update on the lawnmower?

[slewthy]

Well, I went down the fuel starvation line as suggested.

I took apart the carb as far as possible. Diddnt fing any goo or deposits and the emulsion tube/main jet seemed clear. The float and needle valve seemed a rather flimsy affair and came apart with no resistance but no obvious wear.

Anyway, put it all back together and after an age, managed to start it again and, hey, problem has gone!

I'd love to know exactly what it was so that when it happens again (it will) I could replicate the fix but nevermind. Cost - nil. Thanks guys!