can't pull start cord?

When you say that pull start wont turn engine do you mean it is not engaging or has the engine gone tight?
If the engine has gone tight you may have one of a couple of problems.
The engine could have seized up due to lack of lubrication. When there is a lack of lubrication it can be possible for the engine to overheat and bindup/go tight. Then when it cools down it will free off for a short period. This will steadily get worse until one day the engine will lockup completly and wont go again.
Given your symptoms the other but less likely option is (if fitted) a faulty engine brake that is coming on and jamming your engine.
Best to pop your machine to a repair shop and get it checked. If it is the first option you may even be looking at needing a replacement engine.

Robin S
August 2008