I have been surprised to see posts about outboards needing new powerheads at relatively low hours. Sometimes you find boats for sale that are only a couple of years old with less than 200 Hours ( sometimes less than 100) that have gotten a new powerhead. I could see the oil mix being off on a 2 stroke, but you see it on 4 strokes as well. That’s not even enough hours/time to need an impeller change. Someone made a comment to the effect that they all blow , like outboards are a ticking time bomb.
Are manufacturing defects that common, or is there some user error? When I was young it wasn’t unusual for a guy to run the same outboard for 20+ years, but those were 2 strokes that you had to mix the oil yourself.

My boat Is 1 1/2 years old and only has 15 hours on the motor ( I tend to spotlock over good spots and don’t do a lot of running around). The 1st oil change was supposed to be at 20 hours or 3 months- at 1 yr it only had 10 hours and I changed it anyway. I figure I’ll change it every year regardless of the hours. The impeller is supposed to be changed at 300 hrs or 3 years. At this rate I’ll only have 30-40 hours on it at 3 years. Do I need to change the impeller at 3 years even if it has less than 50 hours? Is there something else you can do to prevent early failure?

YES, run it as recommended and not wide open throttle all the time. Most who have trouble are doing all they can to get 1-2 mph. more!

10 hours a year??? I can do that graphing over a weekend, guess I can’t find the good spots.

I've got that beat. I have an '06 Mercury Optimax with less than 40 hours on it.

I try to study topo maps and have a game plan before I leave home. Most trips I only fish 2-3 spots (and sometimes only 1) if I find fish.

I say yes on the need to change the impeller at service intervals regardless of hours used. The issue is that the material deteriorates whether you use it or not. Think of it like trailer tires that "dry rot" and start to fall apart with only 5000 miles of use, but over a period of years. The impeller suffers when it sits not used for long periods. If you used it one a month, it would warm up (from friction) and remain a little more flexible. I've heard of quite a few outboards put back into service that lost an impeller (and sometimes the powerhead if the operator doesn't watch gauges) within 2-3 hours of being used again. My lifelong mechanic buddy says to ALWAYS change an impeller on an engine that has been sitting for anything longer than our (short) over-winter period in Texas.

I don’t know if I’m thinking about it right.. I never run my motor wide open. If I jumped in my ram 1500 and ran that Hemi wide open everywhere I don’t think it would last long! Regardless of the traffic tickets 😎. I see so many folks crank a cold motor and take off!! Run wide open and then shut down. Then over again. I run about 4500 rpm. But I have a 1996 model. I try to make them last.?! Maybe??

Observations from a long time around these silly boats and looking at a lot of trades.

Heat kills more motors than everything else combined. Not even close.

Now the one that’s going to make people mad. The motors that are babied the most live the shortest lives. You might think that’s crazy but it’s a fact. Your outboard is not your truck motor. It’s built to run WFO and it’s perfectly happy running there. The trades that came in with low hours and very low percentage high rpms were the sloppiest and shortest to live.

There’s a fleet of crabbers here, and they are on the water six days a week. Those motors live a hard life, they get run wide open idle to pull traps then wide open to the next set usually 10 hours a day. You can’t read the brand because the cowling is covered in green scum. And yet they expect 6-8 thousand hours out of a motor.

Personally I believe the first five hours will determine the rest of the motors life. Break them in hard and fast and they live much longer. I’ve lost track of some of my old boats but I do know every one lasted at least ten years after I put about 500 on it the first year.

This isn’t feelings this is from witnessing.

Proper motor warm up is important as well. I see many bass fishermen, take the boat off the trailer and dock it while turning the motor off. After parking their truck they jump in the boat and go to wide open throttle on a cold motor. Then they drop the trolling motor, fish for 1hr or more, fire up a cold motor and do it all over again. This can hurt a power head.

I don't think WOT will hurt a motor at all, I run 1+ hour to and from spots sometimes. Not uncommon I put 2-3hrs of WOT on my motor in a full day of fishing. Never once had a power head blow on me on over 5 outboards in 20 years.

Just a side note. I run quality synthetic oil, not the walmart junk. All my outboard shave been 2 strokes and they like to go fast.

Thinks for the replies. I’ve always wondered about the WOT on a cold engine.It seems like I see guys do it every time I go out. You often see posts from guys that have blown several engines over the years, and I’m suspected some of those reports had to be related to how they are driven.

I tried to follow the Yamaha break-in recommendations. After reading posts about SHOs making oil due to rings not seating, I try to run some at WOT every trip out, but not until the motor has been running for a few minutes and not from a dead stop.

How common are failures due to manufacturing defects?

Are you fishing Choke? Maps seem to be wretchedly bad, Navionics is really inaccurate. If you have a good topo map, that seems pretty accurate, which one is it (made by)?

I use a couple of different sources. I use the i-Boating app on an iPad.

I did buy one of Donald Harper’s chips for Choke and Falcon earlier this year to save me some time on those lakes. He emails topo maps to study at home when you buy the chip, but I have to use my laptop to open the maps. Those are nice because they have things like old road beds and house sites that aren’t marked on the I-boating maps. When I first got my livescope, I made a trip to Choke and found a school of bass in 22 feet of water. I caught over 20 there within an hour and never could figure out why they were there. When I got Donald’s chip and maps, it turned out there was a roadbed and a subtle contour change that wasn’t on the i-Boating maps at the spot I had marked.

I use Navionic’s cards in Lowrance units and they seem pretty good, but I wasn’t impressed with the app version.

You're doing it right by studying the maps, and having a plan before hitting the water. I agree with Pat Goff above talking about the first 5 hrs. In reliability engineering, we refer it to as "infant mortality failure". There are the few that are on the tail end of the quality distribution that will fail, and you'll know it early in its life. Good manufacturers design tests to screen these out.

When you hear about these failures, you probably hear about it every single time a motor fails. But you never hear about the ones that just perform. So it seems like a lot of motors fail; but in reality, it's probably just the statistics. Just my opinion.
Tim

Pat what rpm do you prop your outbound at? Running it WOT..