I have a 2.5hp Tohatsu on my canoe. It has always started on the first pull until now. I put the engine away, and when I took it out a week later it takes at least 5 to 10 pulls to start it. I changed the plug and while it runs smoother now, especially at low rpm, it is still hard to start. To make the situation worse, it kicks back while pulling the rope and will almost jerk your arm off--amazing for a little engine like that. I would think that the problem with kicking back would be too much compression, ie. carbon buildup on the piston and head, but how would this happen overnight. Or, could it be something else. Any ideas on this problem. Thanks to anyone who might help.