Unfamiliar engine noises could mean trouble. If the noise wasn’t there to start with the chances are that something is about to fail or break.

Like most bikes the BMW “boxer engine” range has its weak points, and this includes the new generation 1200 & 1250 liquid cooled bikes. The problem is however more specifically applicable to the air-cooled engines, single and twin-cam models.

Over a long period of time, roughly around 50 000km and more the valve seats in the cylinder heads are exposed to uncontrollable run-away heat and as a result eventually come loose. When they initially come loose the engine starts to make an unwanted noise and our advice to you is to stop the bike at that stage.

If the seat dislodges itself, it usually ends up causing catastrophic engine and or valve failure if the bike is ridden any further (1km may end up costing you R30 000 or more).

This happens to both the intake as well as the exhaust valve seats and when it will happen is very unpredictable.  We service bikes with over 200 000km on the clock and the engine is un-opened, it all depends on the riding style.  The damage starts to occur when the rider does long distances with small throttle i.e., 10% throttle over a 100km to 200km distance is harsh, for ambient conditions around 30 degrees C and more.

These bikes can easily ride at 10% throttle in 6th gear around 170km/h for a long distance, and while this feels comfortable on the bike you need to apply some mechanical mercy.  The standard tuning files in the bikes ECU keep the fuelling far too lean for this condition.

To minimise any confusion on this topic I have decided that this is enough info to explain this very common danger zone on these bikes.

It all boils down to – if the engine is making a noise stop immediately and trailer the bike further to save money.

There are preventative procedures to minimise the risk of high-cost repairs which involve either tuning at a very early stage and or reconditioning of heads and replacing all 8 valve seats and possibly even valves.  Once again this will all depend on how the bike was ridden from day 1.

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