Al Outboard engine - clearing out waterways

Check the impeller. The little 2 HP motors are usually pretty bulletproof, particularly if they have been used for a while and clearances are getting sloppy. I ran a Marina 2 HP for almost an hour with only one vane left on the impeller and it didn't seem to bother it much. At least I replaced the impeller and used it for another couple of years, and it was still running when I sold it.
There flushing mixtures for cleaning the crud out of a salt water cooled engine but they are fairly rich mixes of various acids and react pretty rapidly with aluminum.
John D. (johndslocombatgmaildotcom)

Sitting for several years?
Always replace the impellor for an outboard every two years max if its in use, each year if its operated in a river system or other gritty environment, and any time its been sitting for an extended period.
Its possible a lean condition may make it run a little hot from a gummed up carb, but I can guarantee you when you take out the impellor you will find its taken a curved set or is even starting to break down or crack. Impellors are relatively cheap, and dirt cheap compared to the cost of a new or even good used outboard.
Also, when was the last time you changed the gearcase lubricant? You should do that every year, or everytime its been sitting for an extended period. Also relatively cheap and dirt cheap compared to replacing or rebuilding your lower unit.
Bob La Londe

OK thanks all - ill start with the impeller! Charlie+

you know... that's a lot easier said that done. (not the impeller, but the gearbox oil)
Never the less, It's on my list - if the spring thaws ever come...

Actually it is pretty easy... with the right gear. The easy way is to buy the gear oil in one of those "toothpaste" tubes. Take out the two plugs and let the old stuff drain out then jam the nozzle of the oil tube in the lower hole and squeeze. When oil comes out the top screw the plug in. Then take the tube out of the bottom hole - the oil won't leak out - and screw in the plug. Almost quicker to do then to tell.
Cheers,
Schweik (goodsoldierschweikatgmaildotcom)

I use a pump, but basically the same thing.
1. Place bucket under unit. 2. Pull bottom plug. 3. Pull top plug. a. Inspect oil draining from unit for metal particles and color b. If brown you have water in oil, plan on a seal kit. c. If any metal particles larger than tiny slivers, plan on a complete rebuild soon. 4. Pump oil in bottom hole until it comes out top hole. 5. Replace plug in top hole. 6. Remove pump. 7. Place plug in bottom hole.
It's a really good idea to replace the gaskets on both plugs.

I'm sure you guys are assuming that you can actually get to the gearbox.
Probably even thought you'd take the motor off of the boat.
Or maybe the boat is on a trailer!

When I was in that business (a LONG time ago!) we had a 2 gallon pressure sprayer with gear oil. Complete refill took 5 minutes (mostly waiting for the oil to drain), topping off took 60 seconds. Checked every motor that went though the shop.

Actually I use a pump also but I wanted to post the most simple method. You could even use a long hose and a funnel, just hold the funnel higher then the upper hole :-)
Another point is that the seals in the lower end don't last forever and if the engine is used frequently it is a good idea to change the oil on say, a monthly basis. That way if water starts getting in you may catch it before the gears go.
Cheers,
Schweik (goodsoldierschweikatgmaildotcom)

Well, I was talking about a sailboat dinghy motor and La Bonde is probably talking about a bass boat so yes. My motor hangs on the aft rail and his sits on the trailer.
John D. (johndslocombatgmaildotcom)