How long should extra oil be added to a motor for break-In? Does extra oil actually displace some of the gas and create a lean condition? Lastly, what does the additional oil do for a new motor?
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Good question! I’m noticing the OEM’s are talking less about the necessity for “break-in” oil added to the fuel on new 2 strokes these days. No doubt this is at least partially due to the new EPA certification process which monitors actual sleds in the field – from time-to-time.
The concept of adding extra oil is to reduce the piston/cylinder/ring friction created in a “tight” new engine. Essentially the extra oil provides a safety margin as it establishes what is referred to as a wear pattern or as some refer to this as the “seating” of the piston rings.
In any case, a new engine needs to “free-up” a bit by actually scratching (I use this word very carefully) microscopically – the cylinder and the rings. These small scratches are actually good and contribute to a tight seal between the piston and the cylinder.
It usually only takes a short time for this to occur but the most important thing for you to remember is not to squeeze the loud handle for long periods until you’ve got a couple hundred clicks on the odometer. Heat will build up in the rings and cylinder and can create a less than ideal “seal” during break-in.
In today’s electronically controlled world most new 2 strokes have a “built-in” ignition retarding program (Ski-Doo was the first to do this a few years ago) which actually “holds back” the motor from developing full jam – even when you whack it – until a predetermined number of hours has been clocked – usually about 5 hours.
No, the oil will not lean-out your mixture appreciably. Keep in mind – oil flattens gas – it actually reduces octane. Less oil is good. More oil is not so good.
Hope this helps!