Some 'rude 50173s questions

[oldrudedude]

Hi all,

Just bought this 1971 Crestliner with an Evinrude 50173s. This is my first power boat so I'm pretty green although I've been doing self repairs on cars and motorcycles for about 40 years.

There was a broken throttle cable, controller box was torn apart, and the ignition switch was not making good contact. I repaired the throttle cable and cleaned out the ignition switch. I checked the shift switch and it seems to be working as it should (forward = no continuity, neutral = purple to green continuity, reverse = purple to green and blue continuity) (right?). New plugs and tore apart the carbs. Carbs looked real good but I put some carb cleaner and compressed air to them anyway.

Boat came with the garden hose muff thingies that clamp over the water intake.

First question: Which vents are the water intake. The ones forward of the prop or the ones above it?s


When I started the unit I put the muffs over the lower vents because there is no room for them over the upper ones. The water seemed to leak out of various holes but not out of the upper vent as I expected.

The unit went into neutral at soon as the motor started and into forward as soon as I pressed the forward button, but seemed to stay in neutral when i pressed the reverse switch. The green and blue wires going into the final drive unit both read 7.2 ohms. The shift switch seems to be OK. So my second question is: Why don't I have reverse?

You guys seem to have the answers. I hope you can help me with this.

Cheers

 

[larky]

Re: Some 'rude 50173s questions

the water intake holes are the lowest ones, not the ones just above the prop. water will not come out of the upper holes(the two on the back of the leg near the powerhead) until it is submerged in water. they are called exhuast relief holes. they allow the exhuast to exit when there is too much back pressure from the water that surrounds the prop. for the shifting: did you check the amount and condition of the lower unit oil? if not, drain it and refill with type "c" or also called premium blend. available from you johnson/evinrude dealer.

If I am reading my manual right, you are correct with your continuity tests. another test the manual describes is checking the solenoids for grounding to the lower unit case. and the ohms reading of each solenoid. they should read between 5 and 6 ohms.

good luck, let us know what ya find.

 

[tashasdaddy]

Re: Some 'rude 50173s questions

Hydro Electric Shift)
(J. Reeves)

The shifting setup of the lower unit is what's called a "Hydro Electric Shift", which is quite complex consisting of voltage being applied to solenoids in the lower unit which in turn change oil passages via a oil pump that supplies various pressure on a spring loaded shifter dog. The wires leading to the lower unit (at the powerhead) are "Green" and "Blue". The engine must be running or cranking over in order to shift out of forward gear.

You CAN NOT use HI VIS lube in that lower unit. You MUST USE what OMC calls "Premium Blend" lube, commonly called "Type C". (A thinner lube)

In neutral, you need 12v to the "Green" wire.
In reverse, you need 12v to both wires, the "Green" one and the "Blue" one.
In forward, there should be no voltage to either wire. (The spring loaded shifter dog forces the unit into forward gear)

To check the lower unit for proper shifting to make sure you have no trouble there, remove the spark plugs to avoid problems and to allow a higher cranking speed.

This next step eliminates the actual shift switch in case problems may exist there.... Disconnect the blue & green wires at the knife connectors (the rubber insulated boots) leading to the lower unit at the powerhead, then using jumpers, take voltage direct from the starter solenoid to apply voltage to the "Green" wire for neutral, then both wires 'Green" & "Blue" for reverse (Remember the engine must be cranking over in order to shift).
With no voltage applied, the unit should be in forward. No need for a ground jumper... the lower unit's already grounded. You may crank the engine with the key switch or by energizing the starter solenoid with a jumper wire

 

[oldrudedude]

Re: Some 'rude 50173s questions

Thanks for those fast replies. I guess I had a water on the correct vent. I was afraid I had the muffs on the wrong place and I was frying the impeller. Where is the water supposed to come out?

I have check the condition of the oil in the lower unit. There are no filings or evidence of mechanical damage. I will drain the unit and replace with type "C" in case someone installed the wrong oil.

 

[oldrudedude]

Re: Some 'rude 50173s questions

Yahoo Success!

I drained the lower unit oil and replaced it with type "C" until it came out the overflow hole --> still no reverse. Topped it up and started it again -->
still no reverse. Topped it up again and started it --> YES now have reverse.

I guess it was either that the old oil was gumming it up or the level was too low for it to sfift into reverse.

Now how do I tune the thing so it idles in the water? A friend suggested putting the lower unit in a barrel of water. Will that work?

I defaulted the idle stop screws to 1 1/8 turns out, but it sound a little rich. Is it an air screw or a fuel screw? Does turning it in make it richer or leaner?

Thanks to Larky for suggesting changing the oil.

 

[tashasdaddy]

Re: Some 'rude 50173s questions

m 71 50 like the idle mixture screw, 5/8 turn out from soft seated, then fine tuned. you are talking about the adjustment screw and the top center of the carb, it does both. it is the mixture screw, regulates the fuel/air mixture, and low speeds, the high speed in in the bottom of the bowl behind the drain screw, and is a fixed jet, non-adjustable. the idles speed stop screw is on the starboard side, on the linkage.

 

[oldrudedude]

Re: Some 'rude 50173s questions

thanks tashasdady. I'll try starting at 5/8. Should I do the fuel/air fine tuning in the water (barrel as I suggested) or is it OK to do with the muffs?

 

[larky]

Re: Some 'rude 50173s questions

its best to do it in the water. a barrel should work but you may have to tune it a bit more when you get to the water. to set the idle, you should be in the water, in gear and moving( not tied to dock). set idle to 600-700 rpms ( I think that's correct).

 

[tashasdaddy]

Re: Some 'rude 50173s questions

all you can do in the barrel or muffs is get it close, then you have to fine tune in the water, and in gear.