I agree about not using synthetic oil at first, what is happening is you are letting the rings (seat) in the cyclinder so by using a conventional oil the rings and barrel are actualy wearing in to each other creating a nice fit I recomend running about 1/2 to 3/4 throttle varying your speed so the rings dont get used to running at one speed hence seating in one area of the cyclinder more than an other run it like that for a couple hundred kms, vespa recomends 600kms but it will be fine as long as you have the carb jetted properly. After that I would run silkoline 2 stroke pre mix, I have had nothing but great success with it, this oil costs a little more but makes the engine last very well. Good luckRon Brown wrote:
> Read my post again, slowly and carefully.
> I sugested NOT using synthetic for the run-in period.
> I also described galling of metal and siezing as possible
> results of not running in correctly. Some would describe this
> as "blowing the piston" I suppose.
> In addition, when you first get it running, warm it up then
> ride it for a minute or two, then check the spark plug for a
> light brown color. If the color is any lighter than that,
> don't ride until you increase the main jet, a lean mixture will
> make the engine run hot enough to seize and/or hole the piston.