1988 Evenrude - broke the lower?

So i was out just tooling around with my dad and daughter, ran through a shallow spot and that was it. Couldn't go fast anymore, only about 2 or 3 mph. when i rev the motor, it just acts like it doesnt have a prop. idle it home and noticed oil was coming out of just above the prop area.

i don't know much about motors, i could figure it out with some help from you guys so let me know what to do.

im guessing remove the cotter pin and but from prop, undo the 3 bolts on the lower unit and slide off internal shaft to see whats going on. i just want to be sure i do something right.

How much oil are you seeing and where is it coming from exactly. Mabye a pic showing exactly where it's coming from.

will be later before i can get pic but it sat for 3 days before i noticed the oil so i am not sure if there was a puddle or not. it rained so i can not go check the grass. i will be my best though.

It could just be a spun hub. All the older OMC motors I had dripped some oil from the hub, but it was unburned 2 cycle, not lower unit lube.

[url=https://www.tinboats.net/forum/viewtopic.php?p=345565#p345565 said:

muskiemike12 » 2 minutes ago[/url]"]It could just be a spun hub. All the older OMC motors I had dripped some oil from the hub, but it was unburned 2 cycle, not lower unit lube.

Click to expand...

+1 That's what I'm thinking also.

so whats the fix for a spun hub? does the symptoms suggest this? that is pushes my boat but cant go fast? goes in reverse and acts the same. so what is a spun hub anyways? like striped splins that spins the prop? how much to fix if so?

This happens when the rubber part of the prop loses it grip on the aluminum. You can either get a new hub pressed in at a prop shop or buy a new prop. I have had good luck for my small outboards with the Solas Amita props that you can get from iBoats.

what do i take off in order to see or make sure this is the problem? for what its worth, i can not freely spin this prop by hand. it goes to the point where i am pushing against the compression of the motor. i just want to be sure of something before i go ordering something.

What HP is your motor. Just because you cant spin it by hand means nothing. If you are that unsure, I would draw a line from the splines across the rubber to the aluminum. A florescent paint maker will work well. Take your boat out and test it. If the line is broken, then you have a spun hub.

its a 15hp. can you find a diagram so i can better understand? i am searching and not seeing the word Hub on any diagrams i see.

https://www.sterndrive.info/outboardmotor/id10.html

the best i can find. assuming it is one of the horizontal parts, not vertical.


thanks again for your help!!

The hub is part of the prop. If you look at the way a prop is assembled, there is in inner portion (hub), that has the spline in it, and the outer portion which has the actual blades attached to it. The inner and outer sections are held together by compressed rubber between them. When you spin a prop, you damage the rubber so that the inner and outer section can slip/rotate separately when enough pressure is applied. Place a mark on the back end of the hub/prop so the line extends from the center of the hub to the outer blade section. The next time the hub slips, the line will look like 2 shorter lines that don't match up any longer.

The hub is part of the propeller. It is the part between the drive shaft(part of the motor) and the prop.

https://www.tackletour.com/images2/picpropaid03.jpg

Click on the link. It is part B

you guys rock!

so now it is a new prop or this hub and taking it to get pressed in?

next question is, how do i know if i even have the right pitch for my application and if i should just get a new prop as an upgrade; hub would already be in there.

muskiemike12: you helped me in a post about this before.. https://www.tinboats.net/forum/viewtopic.php?f=4&t=32242

i have a 3 blade on there currently and is in decent shape but in no way new and has dents all over the edges. would 4 blade do anything for me? it gets about 21mph with me and with my dad i get about 19mph fully loaded. lately it seems that it spins until i get to a certain speed and the planes out and feels like someone hit 2nd gear or something. you can definatly feel it kick so i am thinking i need a dolphin tale for sure to help me get on plane faster and easier. as for the prop, what do you think?

What motor is it? The evinrudes have a shear pin on the shaft. It will break before damage to shaft or gears. Make sure you don't have one that is broke.
When you pull the prop, it will be a cross pin on the shaft.

I know there is a cotter pin that needs to come off before the nut comes off that holds the prop on. thats all i know. i have never worked on this motor in 2 years of owning. best motor every owned.

That said, the pin is still in place, along with the nut.

sorry for my ignorance on this topic. im learning.

Once you pull the prop off, you will see the shear pin. It will slide out of the shaft to replace.

That motor does not have a shear pin. It uses a castle nut and cotter pin. Your prop will have the pitch and diameter stamped on it. 9 1/4 x 9 or 9 1/4 x 10 I assume. The 2nd number is the pitch. You will loose top end speed with the 4 blade. I would just get and new prop and the prop nut kit as well.

that says for 90hp. mine is 15. also, do you suggest a dolphin tale attachment to get on plane better? its only a 12ft and does pretty good but i would like to be on plane at lower speeds a lot of the time and i find myself going too fast around corners just to stay on plane to get away from slowing down

That is just an example of how to search, or you could see my shopping cart when I posted the link. Just select Evinrude, type in 15,1988 and it will pull up the props that fit. You should not need a hydrofoil or dolefin.