I've finally decided to service my ancient petrol mower, but have no idea what type of oil is needed. It's an old Sigma Prism 37, or so it says on the front. Any ideas? Oh, also any thing I should know about taking a petrol mower apart before I start?
I think mowers need 5W-30, but I could be wrong. i just put in some car 10W-40 and mine still works (warm weather helps!)!
Mower and similar small engines normally use SAE 30 oil, although some Honda engines use multigrade.
I bought a litre of SAE 30 from a petrol station yesterday for my mother's mower. It was for diesel engines, but the small print said it was also
suitable for mower engines.
HTH
Mal
Yep - SAE30, preferably labelled for lawnmowers.
My mower was in the same state - hadn't had an oil change since I bought it, and rarely checked the oil level. A month ago I did check the level
- and it was off the end of the dipstick! 
The old oil was a black goo...
I also changed the spark plug - and starting the mower is a lot easier now.
David
[Edited on 19/4/07 by David Jenkins]
I should definately get around to changing my oil and plug... It sounds rough as a badgers arse when I start it up! SAE30 - that is the stuff!
I sharpened the blade and re-balanced it while I was at it. Now it cuts the grass instead of beating it to death...
I assume balancing is merely a case of end to end, determined by holding it on a pivot where it bolts in? I did also clean the plug as the missus couldn't even turn it over as it had been outside all winter. Bit of WD40 soon solved that though!
I only used a crude balancing technique - a bit of round metal rod across the gap in my workmate.
Not an ideal technique, but quite accurate and the mower runs smoother than before - the blade had lost a few chunks over the past few years.
[Edited on 19/4/07 by David Jenkins]
quote:
I did also clean the plug as the missus couldn't even turn it over as it had been outside all winter.quote:
just like my neighbour, came home and there's his wife struggling with the mower and him cleaning his push bike. Just looked at me with a blank expression when I said 'I see poor Jane's doing the lawn'. How times have changed.
[Edited on 19/4/07 by Mr Whippy]
britishtrident - 19/4/07 at 11:51 AMa Briggs and Stratton engine ?
According to my Briggs & Stratton manual Choice of few grades including -- straight SAE30 5w/30 or 0w/30 or 0w/40 (eg Mobile 1)
I use 5w/30 as used in Ford Zetecs cause I usually have some around.
graememk - 19/4/07 at 12:14 PMmy mower runs of fully synthectic that was left over from the vectra oil change
DIY Si - 19/4/07 at 07:51 PMSo I can basically use any old something/30w oil I happen to have lying around spare?
Mr Whippy, the missus mows the lawn and I look after everything else in the garden, so not too bad. I do tend to start the mower for her and rake up the grass after too!
