I've been told synthetic oil can cause more problems than it solves. I've heard it shouldn't be used during the a motorcycle's first few thousand kilometers as it stops the engine bedding in and that it can cause clutch problems as well. Is this true?

Quote by: bink

I've been told synthetic oil can cause more problems than it solves. I've heard it shouldn't be used during the a motorcycle's first few thousand kilometers as it stops the engine bedding in and that it can cause clutch problems as well. Is this true?

First, there are loads of oils sold as synthetic but most aren't actually fully synthetic. The ones that are will be a bit more higher in price. They can slow down the bedding in process slightly but it's not a problem and as long as they're motorcycle specific engine oils, they won't cause clutch slip.

The clutch slip and damage to the clutch happens because people use car engine oil, which includes friction modifiers, with there motorcycle.

For the newer bikes, fully synthetic will extend the bikes life, however with older bikes 20+years, standard grade bike oils with high Zinc contents are required. As the new oils have become more environmental friendly, they have taken out the 'good' stuff. New engines are designed to run without the 'good' stuff like zinc. One example is the rocker and valve contact area in the old Honda CB125 etc, The local pressure here is very high when you are pushing the motor and Zinc was added for this type of purpose. The new motors with valve buckets have a considerably lower pressures ( kg/mm2) and therefore don't require as many additives.

The best way to extend a motors life is change the oil frequently.

Eg Mobil 20w50 car and 20w50 bike oils are different. The bike oils normally have more additives. I'm told the V-Twin bike oils are one of the best.

Personally I always follow the advice I get from many mechanics who suggest that during the break-in period owners should use non-synthetic oil, and then switch to synthetic after the break-in period is over. It will not hurt the engine so it's a safe advice even if one day we discover it's complete nonsense...

The second and more serious advice is don't skimp on your motorcycle lubrication fluids. Pay for the good stuff. They cost a bit more when you buy them but over time they proof to be cheaper...

A bit more about motorcycle lubrication you can find at Motorcycle Lubricants what to select.