Re: location of impeller
The water outlet on these motors is back through the side of the gearcase, so you won't see any water spitting out.<br /><br />To access the waterpump, you need to remove the rear leg case. This can be troublesome at times due to corroded bolts. Then remove the 6 bolts that hold the gearcase to the leg underneath the seam, and the one big bolt at the back that goes down through the leg and into the gearcase. If this is manual shift, you need to remove the little plate on the side of the leg and undo the shift linkage, the lower bolt only, remove it completly.<br /><br />The whole lower unit should then (hopefully) come away from the leg. The waterpump is the cast alloy piece that is bolted down to the front of the geargcase, with the driveshaft coming up out of it.<br /><br />Before you start any of this, get a manual. It is indespensible.<br /><br />Now,<br /><br />As for the engine running poorly. Have you checked the spark? It needs to jump a 1/4" gap with a sharp snapping blue arc. <br />The bigtwins also have a bit of a habit of only running on one cylinder. Ussually due to age breaking down the wire's insulation on the engine wireing. <br />The other very big problem with these old gems is the ignition coils, the old green and orange colored coils will crack open and short out to ground. Killing any spark. Point's also can get dirty and affect spark.<br /><br />Another thing you should check is the compression. Both cylinders should be above 80 psi (80 minimum, 90 is better, and 100+ is excellent) and be within 10 psi of each other.<br /><br />A carb clean is also a good idea. Rebuild with a new kit that has a plastic float.<br /><br />I know I've covered a fair bit here, but these are the basic things we go through with bringing a Bigtwin engine back to life. Once you get her going right, you'll really love her, maybe not her fuel bill, but the performance is terrific for an old 40!<br /><br />One more thing, Paul Moir and CATransplant are two people you need to listen to on here. If they suggest something with fixing your engine, do it. I will try and get their attention for you....
