1985 25 HP Evinrude - Stops Peeing at Low Speed

[Ruler2112]

I bought my boat used. It's a 14' aluminum Mirrocraft with the front 3' enclosed and has a 25 horse Evinrude on the back. (Model number E25TECOS - a 1985 model according to this site.) The guy I got it from didn't do anything to the boat or engine for at least 8 years; it was actually level with snow when I first saw it, battery and engine still on it. Battery held a charge for about 3-4 days at most, so I replaced it, and I spent a good weekend doing nothing but cleaning crud out of the boat, fixing rotten wood, lubing up the poor engine, replacing shorted out wiring, etc. (Honestly, if I'd have known the boat was in such rough shape, I probably would've kept looking.) It's good though - after a few years, I have everything configured pretty much how I want.

After many tanks of gas with injector cleaner and about 2-3 cans of carb cleaner, I have it so that the engine trolls down pretty well, though still not as slow or reliably as I'd like. (I get down to 1.5 mph and it oftentimes stalls.) The major problem is that as of my trip this past Sunday, the engine will not pee out the side hole unless I'm going ~5 mph or faster; when I slow down, the engine really starts smoking. If I kick it into neutral and rev up, it starts peeing again; I slow the engine down and shift into drive, things are fine for a minute or two until it repeats. I eventually gave up on trying to troll and just cast while anchored the last trip out.

A co-worker said that this is a classic sign that my water pump is bad and needs to be replaced, and that the lower unit needs to be removed in order to do this. I've never had my engine apart, in fact I haven't done anything except grease it, change the lower unit oil 2x a year, change the plugs every spring, and clean it. (Which is far more than the previous owner ever did.) I found a site online (a parts catalog) with exploded diagrams of this engine with all the parts labeled, but it really doesn't show how to disassemble it.

I was wondering if the above diagnosis sounds logical to the more experienced boaters here. If so, can anybody provide advice on where to begin? I've rebuilt 4-stroke lawn mower engines, but never done a 2-cycle. I'm good at taking stuff apart and getting it back together, so I feel I should be able to handle it. I am more than a little hesitant and apprehensive to do so though.

Thanks in advance.





*edit - Also, are there any other things I should watch for when I have the engine apart, assuming that I do indeed need to disassemble?*

 

[1946Zephyr]

Re: 1985 25 HP Evinrude - Stops Peeing at Low Speed

Well, I would check and make sure the pee hose is completely cleaned out before you tear down for a waterpump, but it could likely be the impeller in need of replacement, if that doesn't fix the problem. I too, just picked up a 1986 25hp that had sat for many years, but I'm going to replace the impeller for good assurance. All you have to do, is drop the lower unit and the shift rod coupler will be visible once you lower it. Once you get the lower unit off, then you'll see the impeller housing right there around the drive shaft. There will be 4 screws holding the impeller housing on. Once you lift the housing off, you'll see the impeller. That's all there is to it. Apply a hefty coat of oil on the water tube grommet and drive shaft o-ring, when you re-install the lower unit.

 

[Ruler2112]

Re: 1985 25 HP Evinrude - Stops Peeing at Low Speed

Thanks for such a quick reply Zephyr. I am relatively certain that the hose and pee hole are free of obstruction because when I rev the engine up, the water shoots out at full force. I thought that I'd just sucked in some weeds or something the first time it happened, but that it kept repeating kinda put the screws to that theory. I have had trouble with sucking in weeds (or something) a couple of times in the past - stuck the wire end of a bottom bouncer up the pee hole and it cleared the problem. That was when the engine wouldn't pee at either high or low speed though. (LOL - coast guard must've been laughing at me the one day. Here I was, driving down the river past their station, alternating between going 8 mph <too fast for the no wake zone> and drifting while standing up and leaning way over the back of the engine trying to jam something in the side... )

When you say 'drop the lower unit', how does one go about doing that? I've looked in the past and can't see how it comes apart. Are there any walkthroughs that you're aware of on how how to work on a boat motor that include pictures so that I can more easily visualize what's entailed? Even just a diagram of how the outer housing/lower unit detaches from the rest of the engine would help... I have the detailed inner view from the parts catalog, but don't know how to get to that point.

Thank you again for your time and help. Sounds like it might not be as bad as I originally feared.

 

[trendsetter240]

Re: 1985 25 HP Evinrude - Stops Peeing at Low Speed

If it's been 8 years since the impeller (water pump) has been changed then it's long over due. You should definitely replace it. Also make sure you lubricate the drive shaft while you have the leg off. If the leg hasn't been dropped in 8 or more years it could be seized on.

 

[1946Zephyr]

Re: 1985 25 HP Evinrude - Stops Peeing at Low Speed

You'll see 4 bolts (2 on each side) and a larger stud with a nut, on the very front. Yea, you may have to jiggle it a little bit, when you get it unbolted

 

[Ruler2112]

Re: 1985 25 HP Evinrude - Stops Peeing at Low Speed

If it's been 8 years since the impeller (water pump) has been changed then it's long over due. You should definitely replace it. Also make sure you lubricate the drive shaft while you have the leg off. If the leg hasn't been dropped in 8 or more years it could be seized on.

It's been at LEAST 13 years; I've owned the boat for 5.5 and the last guy had it for at least 8 and did absolutely nothing to it. Frankly, I dunno why he even owned it - he never used it and just let it deteriorate on an empty lot he owned.

You'll see 4 bolts (2 on each side) and a larger stud with a nut, on the very front. Yea, you may have to jiggle it a little bit, when you get it unbolted

These 4 bolts are upside-down the the engine is on the boat, correct? There are also 2 bolts extending out from the housing with a nut on the end that appear to be securing the whole thing to my transom. There are 2 great big fat black washers (literally 1" thick each) under the arm going to the bracket fastened to the transom. If my thinking is correct, I can undo the 4 bolts and then lift the engine portion off, rather than dropping the leg. If I remove the nuts from the two bolts coming out on either side, I don't see what else would be holding the engine to the boat. (And yes, I was outside in my pajamas looking at my engine with a flashlight at 1:20 AM.)

Thank you both for your responses.

Another question - am I able to run the engine like this, as long as I stay over 5 mph, without danger of damaging the motor? We've been absolutely killing the walleye lately...

 

[trendsetter240]

Re: 1985 25 HP Evinrude - Stops Peeing at Low Speed

There are also 2 bolts extending out from the housing with a nut on the end that appear to be securing the whole thing to my transom

You don't need to remove the engine from your boat. In fact it's much easier to do with it still attached.

It's only the lower leg that you remove to change the impeller. Starting from your prop and going up the leg, the first plate is your anti-cavitation plate. The next plate is where the lower leg is bolted on. This is where you need to separate the leg.

As mentioned, there are 4 bolts that are visible that you need to remove and one nut that is "hidden" at the front of the leg which you get at from above.

If you don't already have a manual for this motor then you should definitely pick one up.

cheers!

 

[psteurer]

Re: 1985 25 HP Evinrude - Stops Peeing at Low Speed

You are a brave person if you are going to do a water pump without a manual. I would recommend that you get one. But if not then, once you remove the 4 bolts and one that is hidden you are going to find that the lower unit will slide down about 2 inches and get stuck. The next step is to disconnect the shift linkage. Below are some instructions on that:

There are two bolts that connect the shift linkage. These are located behind the plastic water intake screens. The screens are located above the gearcase and below the cavitation plate. Remove the screws that hold the plastic intake screens and take the screens off. Then you will see the upper and lower shift rods connected by two nuts. Hold the bottom nut with a wrench and open the top nut with another wrench. then slide the top nut up. You will see a black plastic retainer type part that has a split in it. You need to remove that plastic part and then the nut will slide off. You should be able to separate the lower unit after you do this.

 

[jeff_smith_0423]

Re: 1985 25 HP Evinrude - Stops Peeing at Low Speed

Get the manual. Nothing worse than getting something apart and having no clue on how to get it back together.

I would not run that motor with the impeller in that condition.. The extra smoke you're seeing is the layer of oil burning off all the rotating gear in the engine from the increased heat.

Once you do it once, you'll get the hang of it and doing it every other year or so will be old hat - and save you tons of $ on service costs.