Oil in Older Merc 650 (65.0 HP)???

[MercMan69]

I know that the fuel/oil mixture is supposed to be 50:1, however, is there any oil in the lower unit of the outboard, or in the crankcase? If so, what type of oil is to be used? Thanks!

[Frosty]

Merc,--The lower unit is generaly understood to mean the gearbox. There is oil there. This is checked by a stainless steel flat screw-one at the botton and one at the top of the gearbox--only about 4 inches away from the bottom one. Your expected to fill from the bottom untill it comes out of the top.

The crank case does not have oil at all.Lubrication is simply by the oil that you mix with the fuel. This goes through the crankcase first as does all 2 stroke engines. The special 2 stroke marine engine oil and fuel is then compressed and burned in the normal way.

[MercMan69]

Slightly off the topic... When I run the motor with "muffs" on it, the water seems to squirt out of a port on the right (drivers) side of the engine. How ca/n I tell if the engine is circulating water properly, or if the water pump is strong

[Frosty]

Merc --at the risk of making an ass of myself . I will explain this question also --yet I think your winding me up. If im wrong Im sorry.

The squirter as we call it in the trade "the pisser" or a tell tale is there to tell you that all is well.

But why do I think you knew that.

Whats the next question --What is the big heavy black thing with 2 big wires on it?

[PAR]

Water pump impellers should be changed regularly, even if the boat hasn't had much use. It's an easy thing to change, just a few screws and a few bolts. You'll also get the opportunity to change the case oil, as it has to be drained so you can get at the pump.

Do yourself a big favor and pick up a repair manual for your engine. It will tell you how to do the basic maintenance and routine adjustments that are necessary to keep an old outboard running good. It will also help you diagnose problems and provide maintenance schedules, so you can replace parts before they break and mess up your day (usually farther from shore then you'd care to swim back to).

As far as your pisser output, it's best to check for a good flow when the engine in the water, not with muffs. Muffs can fool you into thinking you have good output, but in fact it's the high water pressure coming from your tap, not the pump providing the water stream. Next time you have her out on the local puddle, check the output at idle and with the throttle opened up some. You should have a steady stream, a lot like drinking seven beers in a half hour and then taking a piss. The stream should increase in velocity as the engine RPM's increase.

[Frosty]

Originally Posted by PAR

oil as it has to be drained so you can get at the pump.
.

errrm --Are you sure?

[charmc]

Originally Posted by PAR

Water pump impellers should be changed regularly, even if the boat hasn't had much use. It's an easy thing to change, just a few screws and a few bolts. You'll also get the opportunity to change the case oil, as it has to be drained so you can get at the pump. ...
Do yourself a big favor and pick up a repair manual for your engine. .

Great advice. As far as I know, however, although every outboard requires the lower unit to be dropped to get at the impeller, not every lower unit removal requires draining the gearbox oil. Many allow removal/replacement of the lower unit without draining the oil. It's a good idea, though, to replace the impeller AND change gearbox oil as part of the annual service.

[Frosty]

Not all outboards require the gearbox to be dropped off. Those little 2.5 and 3.5 dont-- behind the prop!!