Re: Motor dies when prop starts to spin...help!
I see guys have this problem all the time, with older boats. Usually the idle screw has just slipped a little bit, so the boat is idling too low. You can fix the problem by just turning the idle screw to raise the idle a little bit. The reason you have to do this is on old carbureted boats the spring that is supposed to hold the idle screw still gets old and looses it's "springiness," so it allows the idle screw to turn out, due to engine vibration. When the idle screw turns out, the idle lowers, so when you try to engage the prop, the engine just isn't running fast enouth to overcome the resistance of the prop. Just turn the screw in a little bit while the engine is running to raise the idle a bit. That will probably fix your problem.
If that doesn't fix it, you may have a dirty carb. Off-idle performance is usually the first place you'll notice problems when you have a dirty carb. Try running some carb cleaner through it, and see what happens.
Finally, if neither of the first two things fix it, the engine is probably just worn out. The low compression of a worn out engine is most noticeable at idle, since that's when the gasses in the cylinders have the most time to blow-by the pistons and piston rings into your crankcase.
Make sure you try raising the idle a bit before you give up! It only takes about a min, and I'm pretty sure it will fix your problem. Good luck!
