A long time ago in a galaxy far away, there was 2 star, 4 star and 5 star petrol with enough lead in it to paint the bottom of a barge.

Your average 2 stroke bike or saw running on a mixture with as much as 16 to 1 would chuck out as much smoke as a 'Saturn 5' rocket on its way to the moon.

Well those days of instant pollution machines have now gone. We're now trying to build machines that pump out less pollution than a squirrels fart !!!!

Fuel now has no lead, full synthetic oil mix at 50 to 1, most of our small engines have catalytic converters combined with Husqvarna own 'E' Tech engines. This is combined with factory set carburettors tuned to run to the lowest emissions in Scandinavia, Europe and U.S.A. These carburettor settings combined with their fuel seem to be OK in general.

In my opinion here in the UK, our fuel is different. It seems to burn hotter, is more aggressive to fuel pipes, diaphragms and seals and goes off quicker. For larger fuel injected, water cooled low revving, high usage engines, the difference would be of no significance.

One of the most usual repairs I have today is overheat seizures. Customers assume it is because they haven't put enough oil in the fuel (this can happen) but it's usually because of a rapid over heat caused by the nature of the fuel. The usual machines subject to this are the older ones (built in the days of 2 and 4 star petrol), they just don't have an adequate cooling air to cope with the extra heat generated.

All new Husqvarnas are designed to run hot, as when fitted with a catalytic converter you need more heat to make it work efficiently. From design they are able to cope with excessive heat stresses put on hem by various fuels.

As we are as yet not subject to the strict emission laws set in the US (particularly California) I personally tune all machines to run at maximum power and mechanical efficiency. This may change emission levels slightly. I have never as yet had an over heat seizure on one of my tuned machines. All Husqvarna machines have adjustment limiters on their carburettors (so the end user can't tamper with them). With special tools I can override these settings for tuning. I mention this because other popular machine manufacturers have no tuning adjustment on their carbs at all. I find when they are brought in for repair they run too weak and can't be adjusted. The only option is to buy a new carb, but this may be no better.

By the nature of chainsaw - brush cutter - hedge trimmer carburettors being able to function in any position, they are of a semi sealed type. The downside of this is that they are affected by atmospheric pressure, the same machine run at sea level and then up a mountain will not perform the same. It is my belief that the factory setting is not ideal for every machine.

To sum up with 'Peter's Power Tuning Plan', give me 2 identical machines and the one I tune will out perform and probably outlast the standard factory set machine.