Spring is upon us, my grass is growing, it's time
to break out the vintage mower - Ransomes Marquis,
Villiers F12 engine.
Trundled down the local garage (Morrisons) with the red
can and found ... no LRP petrol. Checked around town;
none to be had.
So - how do I run my mower? I know that a little unleaded
won't hurt it in the short term, but what should I do?
Are there additives available?
I doubt octane rating is an issue so something to protect the valve
seats is probably what's needed.
I've seen the classic car lot recommend Miller's VSP and google
I use a similar product from Morris in the MGB, it still pinks like
hell even on the optimax type petrol but as I only pootle around and
do very low mileage so I've left the ignition just slightly retarded.
I am told that avgas from a local flying club is still laced with lead
and 105 octane.
There is still one chain of petrol stations that sells leaded for car
enthusiasts, some sort of exemption if total sales are below a small
percentage of the whole.
As it's valve recession that lead inhibits I suppose a head insert and
possibly higher grade valve is all that is necessary and totally
invisible to the outside.
After many years repairing older and some much younger mowing
vehicles/machines I had it on good authority (Textron themselves....Used to
be Ransomes-Jacobson) that the long term effects of unleaded in the engine
you describe will be un-noticeable as it doesn't run for long enough nor
high enough revs to make and significant difference or have any wear
50's or 60's I suspect. The Villiers F-12 is a simple
single cyclinder engine
I suspect my mower is a little younger than any stationary
engine considered "interesting".
Thanks to all; if I see some additive somewhere convenient,
I'll buy it, otherwise (on balance of opinions offerred) I'll run unleaded.
I thought he still did. Aren't DP still doing the odd gig now and then?
Not that I'd have anything to do with the Devil's music, of course.
Only my ex was one of Grace Gillan's nannies around 1984ish, so I
have a tenuous link to the band.
 Ian and Bron's daughter. She's about the same age as my Caz.
Ahem. Leaded petrol was developed in order to inhibit pre-ignition in high
performance aero engines at the very peak of their development. The practice
was continued into post-war petrol supply in order to use lower octane
petrol in higher performance motor vehicles than they would otherwise
tolerate. It is true that the lead did no harm at all to valve seats and
guides in highly stressed engines, but the point is that unless your mower
is fitted with a desmodromic Ducati racing engine or a sawn off Merlin, it
will run very cheerfully for an extended period on Pool petrol - which
rarely reached the 85 octane rating that was loosely attached to it.
Honestly, change the oil each spring (using a decent SAE 40 like Duckhams) &
use unleaded straight from the pump. If you just add a squirt of modern
two-stroke oil as an upper cylinder lubricant, it will be enjoying far
better lubrication than its maker ever envisaged!
Usual disclaimers as I have always avoided hubris!
In spring, a man's fancy lightly turns
to thoughts of getting his motorcycle on the road!
FWIW I ran a 1300 cc Fiat Uno on unleaded from from 56,000 miles to
136,000 miles & if the body hadn't fallen apart I'd be running it now on
unleaded ! I also did about 40,000 miles using unleaded in a 1500 Allegro.
Both engines had first on leaded.
Unfortunately not but, 15 years ago, I did work alongside a David Coverdale!
When announced at external meetings or conferences it was quite amusing to
see certain people suddenly 'wake up'.
Perhaps we should have offered to have a go at 'Smoke on the Water' on
spoons during the breaks (not).