Depends on the design. Most modern two strokes are designed to run on ULP.
Check the manual. Some of these require high octane ULP.

I have a GoPed scooter with a Zenoah engine (similar to Ryobi whipper
snipper engine) that has high compression and advanced spark to give extra
performance and it definately requires the quality petrol with a good
quality oil. I run it at the book value 25:1 mix.

Leaded fuel will cause deposits that can create problems in engines, but
most of the times this is encountered with aircraft fuel which has about ten
times the lead content of normal old super. The main problem is a buildup of
lead on the valve stem causing the valve to stick. I don't see this occuring
with two strokes but they may build up deposits somewhere else. The
designers probably test their equipment with a range of fuels to see what
happens and how many warranty claims they will have to pay.

My chainsaw and whipper snipper both run on ULP and both are over ten years
old. They get used on my farm and get a good workout, the snipper in spring
and summer, the saw in winter to feed the wood stove. I run them a little
oil rich at about twenty to one rather than 25:1 so they smoke and I have to
replace plugs more often but this way they last. The mufflers could get a
buildup of ash, but I haven't had problems.

Use fresh good quality fuel so they start easier and only mix enough to
cover about two weeks at a time. I mix about five litres in a batch.

Hope this helps,
Peter



"Andrew G" wrote in message
...
Hi everyone.
Just wondering if anyone knows the best fuel to use in 2 strokes, whether
it
be lead replacement fuel (LRP) or Unleaded?
Being a car enthusiast I understand all the differences between the 2
fuels
and have heard many pros and cons for both, but basically LRP for old
leaded
fuel cars, and unleaded for the newer ones, or even the optimax, and other
equivalents as long as it's from a well known servo with a high turnover.
Anyway, when it comes to 2 strokes I was wondering if ULP or LRP is best?
LRP does have a lubricant in it, so when adding the oil for 2 stroke, it
could only help.
In general LRP has a higher octane rating (or it did have).
Apart from being cheaper, I can't see any benefits of ULP. There is no cat
converters in 2 stroke exhausts for LRP to harm.
Just wondering if anyone has opinions, or has heard anything?

Thanks in advance.
Andrew