72 Rude 25 HP runs but stops under load?

[brizander]

I seen this add. Curious if anyone has any idea what the problem would be before I go look this weekend. Sound like motor runs great but problem is when in gear. Here if the add description. Any help would be appreciated.

For sale is a 1972 25 HP Evinrude Tiller motor..It also comes with the fuel tank and stand pictured below.. It does need work that's why i am selling it for so cheap. I'm going to be 100% honest. It starts and runs good when its out of the water and running on bunny ears and a hose.. The motor itself runs very well.. but when I brought it to the lake it started right up and ran perfect in neutral then i put it in gear and at low speeds it was fine and it pushed the boat but when i gave it gas to speed up it started to go but then it stopped pushing the boat.. the motor reved up but the prop seems to stop spinning and it only does this under a load.. The engine of the motor is good so i think its just a problem with the linkage or the gearing or something! i dont know anything about how these things work so I am being very honest and trying my best to describe what the motor is doing.

 

[kenmyfam]

Re: 72 Rude 25 HP runs but stops under load?

Could be as simple as a spun prop hub. If so a re-hub of the prop or a new prop will solve the issue. Having said that I am not certain of that year and HP set up. Could be a bad shear pin if that vintage motor uses them. Could also be jumping out of gear when a load is applied to it which is considerably more of an issue. Could be an entire lower unit rebuild.
My friend has an old Ted Williams 5.5 hp air cooled that he inherited when he bought his cottage. Got it going and had the same issues. It was just a shear pin that needed replacing. Tested it out by putting it in gear and gradually applying a 2 x 4 to the edge of the prop when in gear. As soon as you put some resistance to it then it stopped spinning. Be very careful though if trying this method and make certain you know which way the prop is spinning.
Good Luck.

 

[brizander]

Re: 72 Rude 25 HP runs but stops under load?

Hey Thanks Ken.

Thats a good start for me. Crossing my fingers that it's something that simple.

I'll have to ask him a few more questions. I'm thinking that the way it happens might give an indication.

Thanks Bud

BZ

 

[kenmyfam]

Re: 72 Rude 25 HP runs but stops under load?

Good Luck.
I would however do a compression and spark test on it before buying it and see if it is pumping water.

 

[14ftgrumman]

Re: 72 Rude 25 HP runs but stops under load?

There is no way to put muffs on that motor. If he's been "running it on bunny ears", plan on a new water pump kit. That motor has to be in water, 1/2 the way uo the lower unit.

 

[14ftgrumman]

Re: 72 Rude 25 HP runs but stops under load?

There is no way to put muffs on that motor. If he's been "running it on bunny ears", plan on a new water pump kit. That motor has to be in water, 1/2 the way up the lower unit.

 

[brizander]

Re: 72 Rude 25 HP runs but stops under load?

wow good to know 14ft. I guess he is BSing some then. I'll have to call him on it then when I see him tomorrow. Someone else is checking it out right now. We'll see if I get the chance.

Thanks for the help guys.

He is asking $200 btw. Figured if problem is minor and has good compression then it would be worth it.

BZ

 

[14ftgrumman]

Re: 72 Rude 25 HP runs but stops under load?

I've got 2 got 2 of these motors. Excellent running, minimal maintaince and easy to work on. Also have enough spare parts to make heirlooms out of them.

Sorry for the double post, my mistake.