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1984 Evinrude 4hp - prop doesn't turn

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mpierich

New member
I got the motor recently with a boat. Got the engine starting and running well. But the prop doesn't engage.

It has a neutral/forward control (tho the lever is broken off). Neither position make any difference.

When I turn the prop by hand, it moves with a little resistance but it's clicking like it's jumping teeth on a gear.

Is it likely to be the shifting dog, the gear teeth, or, could it be the clutch?

Never work on them, for now not buying a $30 manual to fix a $30 motor.

Thanks!
 
mpierich said:
I got the motor recently with a boat. Got the engine starting and running well. But the prop doesn't engage.

It has a neutral/forward control (tho the lever is broken off). Neither position make any difference.

When I turn the prop by hand, it moves with a little resistance but it's clicking like it's jumping teeth on a gear.

Is it likely to be the shifting dog, the gear teeth, or, could it be the clutch?

Never work on them, for now not buying a $30 manual to fix a $30 motor.

Thanks!
Click to expand...

They have a funny spring clutch mechanism in them, not the usual dog clutch, but have you checked the prop hub and the drive pin.

See here for exploded diagram of lower unit

http://www.marineengine.com/parts/j...BRHCRM&manufacturer=Evinrude&section=Gearcase

Thre is a Seloc Manual here that covers the engine in general , but not the right gear case for some reason.

http://162.144.28.33/lib/evinrude/manuals/1971-1989johnsonevinrude.html#/0
 
Last edited:
Thanks! Well, I took out the cotter pin, removed the prop, replaced the prop, replaced the cotter pin, and it works! For the time being.

Should I still tear it apart - hate to have to row a half-mile if I don't have to, :) Also, the neutral/forward thing doesn't work - it stays in gear. Is that worth taking it apart to see what's up?

Thanks again!
 
You can but try it !
have you checked the oil ?
If not clear and bright probably the seals need changing

Very small engines are not too bad without a neutral. My Seagull has a fixed drive but its only about 1½ hp. By the time you get to 4hp a neutral is highly desirable.

When was the last time the water pump impeller was changed. If not recent, or you dont know, it may well be worth changing it. While you have the lower unit off take a peep inside it.Also change the seals if in any doubt. All pretty simple... no rocket science.


These 4hp can get the water channel between the leg and the power head blocked... if you have any over heating problems that a new pump impeller does not fix that is where to look
 
Found out that the prop shaft has a good 1/8" end play - that's how far I can pull the prop away from the housing. When I do that, it partially disengages and turns by hand, with some clicking.

Could that be a weak clutch spring? If it's the gears the motor is junk, judging by the price of a new gear.


vics said:
You can but try it !
have you checked the oil ?
If not clear and bright probably the seals need changing

Very small engines are not too bad without a neutral. My Seagull has a fixed drive but its only about 1½ hp. By the time you get to 4hp a neutral is highly desirable.

When was the last time the water pump impeller was changed. If not recent, or you dont know, it may well be worth changing it. While you have the lower unit off take a peep inside it.Also change the seals if in any doubt. All pretty simple... no rocket science.


These 4hp can get the water channel between the leg and the power head blocked... if you have any over heating problems that a new pump impeller does not fix that is where to look
Click to expand...
 
mpierich said:
Found out that the prop shaft has a good 1/8" end play - that's how far I can pull the prop away from the housing. When I do that, it partially disengages and turns by hand, with some clicking.

Could that be a weak clutch spring? If it's the gears the motor is junk, judging by the price of a new gear.
Click to expand...

I don't know what would allow the shaft to have that much end float but it may have caused damage to gears although in normal operation the thrust would keep them fully engaged.

A case of dismantling and inspection to determine the cause I think.

If you paid little for it you can at least afford spend a little extra on repairs . OTOH you will not be losing a fortune if repairs are uneconomic.
 
There are thrust bearings and washers you need to take it apart and see what is going on inside. I rebuilt one two years ago and had to replace the thrust bearings/washers and clutch spring. You need to pull the powerhead and disconnect the shift rod you may as well replace the shift lever at the same time. You need to change the seals and o rings piece meal i couldnt find a seal kit at the time. Hopefully you wont have to replace the gear set more than likely the spring is shot as well mine was broken in half.
 
vics said:
I don't know what would allow the shaft to have that much end float but it may have caused damage to gears although in normal operation the thrust would keep them fully engaged.

A case of dismantling and inspection to determine the cause I think.

If you paid little for it you can at least afford spend a little extra on repairs . OTOH you will not be losing a fortune if repairs are uneconomic.
Click to expand...

Thanks, I might fool with it some, just so I can sell it running. I need a bigger motor anyhow.
 
kimcrwbr1 said:
There are thrust bearings and washers you need to take it apart and see what is going on inside. I rebuilt one two years ago and had to replace the thrust bearings/washers and clutch spring. You need to pull the powerhead and disconnect the shift rod you may as well replace the shift lever at the same time. You need to change the seals and o rings piece meal i couldnt find a seal kit at the time. Hopefully you wont have to replace the gear set more than likely the spring is shot as well mine was broken in half.
Click to expand...

Thanks, probably the spring. I'll have a look.
 
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