92 Mariner 25 HP - 2 questions

[BigEdV]

I just inherited a boat with a 25 HP Mariner outboard. The things engine looks like the day it came out of the showroom but the bottom end appears to have had some abuse (I know it was borrowed a few times while the owner was sick and I think they just did not treat it well).

Q1) I have new prop for it since the old one has a chunk out of one of the blades. Today I was cleaning the motor up and notices there is a large plug on the underside of the "plane" (not sure if that is what it is called but it is the widened out part that is directly above the prop), The plug is about 2" across but 1/2 of it is cracked off and missing (appears to be a cast plug). Can anyone tell me what the purpose of this plug is and what is the damage that may have been done if it was run with it broken?

Q2) there is a lever on the side that says shallow drive and I see if moves a lever on the side of the motor slightly; can someone tell me what that actually does?

Thanks for the help - I know I have a lot to learn yet and would like to know that the boat is safely ready to go in the water before the first launch.

 

[latin monkey]

Re: 92 Mariner 25 HP - 2 questions

to answer your first question, that is where your trim tab or "anode" goes. it helps with stabilizing and also helps keep corrosion away from your lower unit. I'm not sure about your second question.

 

[sxmerc]

Re: 92 Mariner 25 HP - 2 questions

Yes that is a trim tab anode. The fin it sounds, is missing. This may explain at least one of the dings in your prop. The shallow water drive, if working correctly, will enable you to run the motor at a higher positive tilt while in shallow water for prop and skeg clearance. Hence "shallow water drive". If you push the lever down, and then raise the motor up about half way through it's tilt range, a plastic bracket should drop down from under the swivel housing. This bracket will stand on the tilt pin, raising your running height by a few inches. Be forwarned, this is to only be used while in FORWARD gear. While in shallow water position, the motor is not locked down on the tilt pin, and will jump up in reverse at anything more than idle speed. To dissengage shallow water, lift the lever up, then raise the motor up a few inches manually, and the bracket will fold back up out of the way. Drop motor back down onto the tilt pin, and you are back in normal running mode. I hope this help.

 

[BigEdV]

Re: 92 Mariner 25 HP - 2 questions

Thanks for both of the answers it is VERY helpful. Looks like I need another new part to get the boat ready to go.

 

[Mi duckdown]

Re: 92 Mariner 25 HP - 2 questions

Check your lower end lube. and pump impellar, before you get too involved.
My .02

 

[BigEdV]

Re: 92 Mariner 25 HP - 2 questions

Thanks Mi - yes lower lube is good (I checked that already) will have to look into impeller pump. Mechanically the boat was well taken care of - I think the last person to borrow the boat just was not careful and did some damage.

 

[Mi duckdown]

Re: 92 Mariner 25 HP - 2 questions

Thats good. change the impeller. you will sleep better.

 

[BigEdV]

Re: 92 Mariner 25 HP - 2 questions

Just got done reading up on it. Does not look too bad of a job. Thanks for the advice Mi. I will be adding that to my list of maintenance tasks that need to be done annually.

 

[Mi duckdown]

Re: 92 Mariner 25 HP - 2 questions

BigED. the impeller needs to be done before you run the waters, since you have no idea since it has last been changed. MY .02 Seriously

 

[BigEdV]

Re: 92 Mariner 25 HP - 2 questions

BigED. the impeller needs to be done before you run the waters, since you have no idea since it has last been changed. MY .02 Seriously

Sorry I intend to change before and add to annual list.