Re: Help please - First time boat owner
Hah! I used to think that way, then I got a manual. I liked it so much I got two.<br />The thing about the impeller is this, it's supposed to have it's blades pointing straight out like a star. If your impeller has any out-of-roundness to it, that's called a set. In addition to it not performing well in this state, they have a tendency to fly apart and clog up water passages. A new one's under $20. This is not the part you want to be frugal with.<br /><br />Sounds like your thermostat is missing. Probably to cure an overheating problem from the bad impeller.
Everything underneath the plastic sleeve is correct, it's just that there should be a thermostat before (inside) the plastic sleeve. Your engine will run much better with a thermostat then without, especially at idle.<br /><br />You may be able to tell by performance, if you can accurately compare it to previous performances. A compression test is a good idea just to guage the health of the engine. <br /><br />As you noticed when you disengaged the shift linkage through the access plate in the midsection, you have to completely remove one of the bolts on the coupler in order to get it off. The round of the bolt's shank keys into that groove in the shift rod. So it's non-adjustable and should go straigt back together.
<br />It is very important that you lightly grease the splines at the top of the driveshaft before reassembly, and replace the o-ring up there if it is degraded. Anti-corrosive grease works best. If you fail to do this, the driveshaft is lible to become corroded and bound to the crankshaft, making your next impeller replacement much more difficult. Also, I suggest your put a coat of permatex #3 aviation sealer (available at most auto supply places) on the lower unit bolts before reinstalling them. They'll come out again next time if you follow this step.
<br /><br />When installing the impeller, turn the driveshaft clockwise (the same way as your engine turns) as you push the impeller housing over the impeller. It's not a big deal if you do this backwards, apparently these long-bladed impellers will flip when you start the engine. I don't expect that will work for a used impeller though.<br /><br />Still think a manual is useless?
<br /><br />EDIT: I forgot to answer your first question. The original tachometer for that engine was made specifically for 50's-60's OMC 40hp and under engines. They are rare now. A regular outboard tach will not work, since they're not designed to operate with the magneto ignition system. Tinytach, which hooks up to a spark plug lead (inductive pickup) works fine. Unfortunetly, the folks at TinyTach have apparently been less then helpful lately.
<br />It's worth a try though. They work well, and are pretty inexpensive. <br />
TinyTach
