I picked up this motor at an auction for $50. It fired once when I got everything set up. So I changed the coils (very bad and fell apart when the came out). Then regapped the points, and did a carb rebuild. Now it starts and runs well (I will need to get some input on adjusting the low speed needle) but didn't pump water. I changed the impeller which was also in bad shape and it pumped very well at first. coincidently I resealed the lower unit and put it back together, now I am getting just a trickle from the pee holes and nothing out of the exhaust snout. What happened? And if a chunk of the old impeller traveled into the cooling system, how do I get it out?