[amc]

Its check and start petrol engined tools for me this weekend. I'll be following gwiz's advice here:  http://chat.allotment-garden.org/index.php?topic=32617.0  to get the 2 stroke petrol strimmer up and running... I of cousre left petrol in it 

I've also a 4 stroke, 3.5hp, Briggs & Stratton modernish ( ie 10-12 yrs old) rotary mower which, gulp, hasn't had an oil change since my father gave me the beast four years ago. Its had some v. heavy use so it might be time for an oil change....

How do I change the oil? I don't have the manual - I can only see an oil filler cap that contains the dipstick. Do i just simply turn the mower upside down to pour out the oil or is there a drain plug hidden somewhere. Also will it be worthwile to start it and warm the old oil slightly so it thins out a bit to aid draining?

many thanks amc

[Gwiz]

for gawds sake don't tip it upside down!

remove the spark plug, tip the mower bacwards onto the handles.
underneath the engine, near the crakshaft, you should see a sqaure (3/8ths drive) socket. undo that, and the oil will run out.

don't forget to have a container handy (old sweetie/biscuit tin handy) to catch the old oil in.
you can start it before hand, I don't bother as a rule, 'cos I'm a clumsy so and so and just burn my hands on something hot!

[Paul Plots]

Strangley enough I was thinking I ought to change the oil in my mower. Bought mower last season - it has probably done about 25 hours by now so.......

Thanks Gwiz for the reminder of "how to...."

I'm not so sure I'd want to leave my mower with the same oil for years.

[Gwiz]

niether would I!
oil's cheap. Engines 'aint

[amc]

Phew, glad I asked! I'll follow your instructions carefully Gwiz. Thanks v. much for the advice.

Yes I know using the same oil for a number of years is v.v.v bad    I'll try and make it up to the mower with a new spark plug. 

[Faz]

I thought I would chip in, as yesterday i changed the oil in my much neglected rotary mower. I have had it probably 7 years or so and it has never really been looked after, but has always been incredibly reliable. When i say never been looked after, I mean left parked under a bush for a winter, no oil changes, barely any oiling of moving bits until recently.

Anyway, the oil that came out looked like black sludge! I think I will treat it to another oil change in a few weeks once this lot has rinsed out anyway remaining gunge in the casing.

So thanks for the timely reminder and advice!! I promise to look after it better in the future 

[amc]

I did change the oil yesterday and boy was it black, thick and nasty

However the mower now starts easier, runs more smoothly and the exhaust is clearer... my lesson is learnt and being as though how easy it was to do I'll make sure I do this twice a year.

Cheers gwiz for the advice - couldn't find a square (3/8ths) drive bolt on it tho. When I gave the machine a rough wipe the oil dipstick cap said DRAIN - FILL on it so thats where the old oil came out when I tipped the machine onto its side - and not upside down

Ta amc

[Lee G]

Only just spotted this thread, ironically the day after I got my petrol mower out for the first time this year, and I was thinking about this very subject.

It was given to me by the old couple next door when they moved into sheltered accomodation, I've had it for 3 years now and it's never had an oil change in that time.  Started OK yesterday, but I noticed the exhaust was more noticeable than I remember from last year, and I need to keep the choke well out otherwise it stall, so I think I'll try an oil change too.

[Faz]

I would chuck a bit of redex through it too - sounds like the carb might have a bit of gunge in it if you needed to keep the choke out.

Also give the air filter a clean - any oily crud will come off with a bit of petrol (assuming that the filter is a sponge and not paper!).

[Gwiz]

it could also be down to the age of the fuel.
If you've had it kicking around since last year, it may very well have gone a bit "stale". that would explain why you need to give it a bit of choke to keep it going.
I wonder what type of engine you have? is it a briggs? The mention of a choke makes me think that it might not be, or that it's not one of the "classic" classic engines.
You might find that if you have a "carb bowl", it could have a little bit of rubbish in there, and as that is often where you will find the main jet, that would explain the need for choke also.
keep us posted!

[Lee G]

It's a Honda HR173 whatever that means !!

Time to google it me thinks, see where I find the drain hole, air filter and carb.

[Gwiz]

That model has a drain screw.
On the carb bowl, at the very bottom there is a 13mm headed bolt. Just to one side is a screw. That is the drain.
those mowers are prone to "cable slip" so you might find that you just need to adjust the cable a little to get bet results.
The air filter is usually made of foam, so washing it out will clean it. I don't use petrol (H&S reasons) but parrafin works very well and is less "flammable" You should then dry the filter, and put some Fresh oil back on it, wring out as much of the oil as possable, and refit it. The reason for doing this, is because the oil helps to trap the very fine dust particles that a dry filter would let pass through.

[Lee G]

That model has a drain screw.
On the carb bowl, at the very bottom there is a 13mm headed bolt. Just to one side is a screw. That is the drain.
those mowers are prone to "cable slip" so you might find that you just need to adjust the cable a little to get bet results.
The air filter is usually made of foam, so washing it out will clean it. I don't use petrol (H&S reasons) but parrafin works very well and is less "flammable" You should then dry the filter, and put some Fresh oil back on it, wring out as much of the oil as possable, and refit it. The reason for doing this, is because the oil helps to trap the very fine dust particles that a dry filter would let pass through.

Gwiz you are a star, I really appreciate the advice, especially as I'm donating my old electric mower to my Mom - she's collecting it this weekend so I will no longer have a back up!!