[mikelebron]

How long was the bike sitting? Has it done it since?

Some times knocking can be caused when the oil has pretty much dried up and settled to the bottom of the engine... The oil will take time to getting to normal operating temperatures and relube the entire engine especially 1. if your using shitty oil (this is why synthetics are better) 2. And if its real cold outside

 

[mikelebron]

mjw930, you may have never heard of this because you do live in FL and the oil will stay at someowhat of a normal operating temperature, though the issue could happen if the bike sits for a long while. I learned of this issue years back during my more mechanical tinkering days... I learned with a mustang that I had which sat for a little while in the winter.

Old oil which losses its viscosity/lube powers will not stick and not flow like new oil until warmed up. Synthetics rarely have this issue due to their ability to keep their viscocity under most conditions (environmental or engine/oil wear). Sythetics do not break down as easily as good old dino oil..

I agree that lubrication occures the moment the system builds oil pressure, the issue you have in the North, due to the thick oil sitting at the bottom of the engine is that it could take up to a couple of seconds for the oil to start circulating at normal pressures. During these few seconds knocking and grinding can occur.. You will also have this issue if your oil pump is not opperating at its full potential.. Most engine components will work at their full efficiency when warm... and when the oil system is fully pressurized.

If the knocking occurs for more then a couple of seconds shut that engine down... Though knocking may be due to piston slap it could also be bearing noise.. A failed bearing would be catastrophic to an engine. This is why most will tell you DO NOT beat your bike/car until you are at full operating temperature... Most oils are not working at their full potential UNTIL they are warm..

If you encounter this issue often, even after use have the engine serviced. Knocking is NOT normal for the most part.

Since most engines operate on the same princple.. found a good article to re-enforce what I stated.

http://www.pre-luber.com/fall98diyart.htm