| There have been a lot of problems in the USA with excessive piston ring blowby on 998 engines, the cause is not proven BUT it is very likely that not using the full rpm range after about 350-500 miles (albeit not at full throttle) is causing the bores to glaze preventing the rings bedding in.
I work in the motor trade and modern fully synthetic oils are so good that many manufacturers have a first oil change at 10,000 miles! On all my bikes I have started with small throttle openings and progressively increased tha amounbt and duration of throttle opening untill around 1000 miles.
My original 916 is still running well has the same compresion as it had at 500 miles and has no wear on the camshafts.
There are a lot of myths and stories about running in but with modern manufacturing tolerances and synthetic oils you should be able to thrah the bike from mile 1 without too much loss of engine life, In fact bikes that have been abused from day 1 tend to produce more power due to lower friction losses inside the engine
I would not hestiate to buy an ex rental car as long as the service history was up to date even though they are all abused from the moment the first customer takes them out.
dave  |