Changing the impeller

We've had reliable service from our '74 Ericson 32's A4 over the now nearly nine seasons since we purchased the boat, but I hate to admit that I've never been able to change the water pump impeller. I've tried on two previous occasions with no success, and this is one of the reasons why I ordered your Service and Overhaul Manual last week. When I mentioned this to the very friendly fellow who took my order, he willingly walked me through what sounds like an easy and straightforward operation - "just take the cover off and pull". So armed with this professional knowledge I made another attempt over this past weekend and you may have guessed by now that the old impeller still remains in the pump housing. Thus I was looking forward to receiving the manual, convinced that somewhere in its pages there would be a clue - it arrived earlier this morning and sad to say, it provides even less information about this necessary operation than what I had already learned over the phone. Clearly our pump is a late model Oberdorfer and I understand the concept of the shaft and impeller coming out as a set - the problem is that I can't get enough of a grip on the impeller and even though I now realize that I can pull without damage, no amount of exertion has yet to free the shaft/impeller from the drive slot inside the engine. You must realize that attempting to change an impeller on this boat is a 'blind, one-handed operation', and that one hand is working backwards. I even made a 'puller' out of stiff wire in an attempt to reach through the blades to get a grip under the inner face of the impeller, but it's so tightly held against the housing that this had no effect. I also tried pulling on a blade with a needle nose pliers, but by that time I was afraid I'd end-up damaging the existing impeller to the point of disabling the boat. Obviously I gave up and put the cover back on. The engine is still pumping fine - it always has, but that impeller has probably been spinning much longer than we have had the boat. Do you have any ideas for a guy who's already purchased your book? I suppose we could just keep going and going, but at some point changing the impeller will become an emergency rather than what is now just perceived as an overlooked need. I can't believe that I'm the only person that has ever had a problem with this. Thanks in advance for anything you might suggest. Bill Dimmitt - Sioux City, IA