In message , David Hill
writes
On 29/08/2013 18:24, David Rance wrote:
In message , Baz writes

David Rance wrote in
:


I took some of my 2-stroke gardening implements in for service/repair
recently. One piece, a brush cutter, needed a new carburettor. The
proprietor recommended the use of Aspen ready mixed alkylate fuel which
claims not only to be clean for the environment but is better for
2-stroke engines.

There's plenty of info on the web about claims for Aspen fuel so I won't
repeat it here. But what I'd like to know - is it worth it bearing in
mind that it costs more than twice what petrol does? Does anyone here
have any experience of it?

David


I don't know the answer to your question. BUT I think that it is always a
good idea to use the reccomended fuel and lubricant for each machine.
The wrong fuel can cause problems with ignition timings. Making the thing
run hotter or cooler than it was designed for. If hotter you could get a
nasty hole in the piston, or worse it could melt the piston and the
connecting rod can burst through the crank case.
The reason for the ignition timing issue is that an engine is set to fire
at (x)degree before tdc(Top Dead Centre) with the reccommended fuel.
A more combustable fuel would want to fire before (x)degree, and it will
do. That means that it is now trying to force the piston DOWN but the
inertia is probably going to put it at tdc and it will finish it's
stroke.
That is going to build up excessive heat. and reduce performance,
eventualy
destroying crank case compression.(2stroke engines rely on crank case
compression)

Bet you wish I had not replied. It IS a bit intense. If you want I would
love to give you a description on the 2 cycles of a 2stroke engine,
and why
it needs oil in the petrol, and why only not lighter fuel.

Thanks for those thoughts, Baz. Yes, I am familiar with the workings of
2-stroke and 4-stroke engines (I learnt about 4-stroke engines in the
CCF while at school and my father was a motor engineer amongst his other
attributes before and after WWII). Indeed I used to do all my own car
servicing in the days when one could do such things and they weren't run
by wretched computers!

Anyhow, at the risk of being accused of advertising (which I'm
definitely NOT doing as I simply want to know of others' experience of
using Aspen) could I recommend you to the following pages and then let
me know what you think:

http://www.aspenfuel.co.uk/products/...en-alkylate-pe
trol/

David

Your link didn't work but this did
http://www.aspenfuel.co.uk/

Yes, it was a bit long and presumably you didn't get the whole thing in.
I should have done a tinyurl for it.

Looking at their suppliers I'm not going to travel around 60 miles or
more to get fuel

Fair enough! Stockists are a bit thin on the ground in your area but I
think they're trying to increase their outlets so, if it catches on,
more places will stock it. I hadn't heard of it before so I think it's
fairly new.

David

--
David Rance writing from Le Mesnil Villement, Calvados, France