View Full Version : What "mileage" can I expect out of an outboard?

09-22-2005, 09:54 AM
I run my outboard continuously for 4 hours yesterday. *That was the longest I've run it continuously; most of the time I fish close to where I launch the boat.

The question of "mileage" popped into my head: How many miles, or hours, of trouble free operation can I expect out of a new outboard?

Take cars for example, a new Ford is generally expected not to any major problem for about 50K to 60K miles (and then warrantee runs out and problems start >:(). *So is there a general number of hours where an outboard will run trouble-free before problems start to emerge, assuming proper maintenance is done?

If outboards can perform like cars, based on my usage of about 30 hours per year, wouldn't that mean my Nissan would last 30 years? Sounds too good to be true...

09-22-2005, 10:43 AM
Maintenance is everything with regard to any engine's duty cycle. For those big older 2-strokes, very few make it past 1,000 hr. Smaller engines tend to last longer since they are not usually asked to work as hard as the big ones.

4-stroke engines last much longer. My 8 hp Honda is now approaching 2800 hr and all I have done to it (besides changing the oil and the lower unit lube) is 2 sets of spark plugs, 2 thermostats, and a new impeller. *Larger 4-strokes are routinely logging 5,000+ hr without significant problems. *Those little Nissans, while not sophisticated, have remarkable reputations for holding up under all sorts of abuse around the world.

The major wear issue for outboards that are not run very often are corrosion and stale fuel. *An infrequently used engine will not last as many total hours as one that is used frequently. But at your rate of usage, 30 years sounds very possible if you take good care of the engine. Whether there will be fuel available for your engine in 30 years is another issue.

09-22-2005, 11:01 AM
Just .02 cents. I have a 14 hp Goodyear that was handed down from my Dad. I think it was built in the mid 50s. The case even has "tail fins". I use it on my duck boat. To my knowledge we have always done preventive maitenance on the motor and have never had any large problems. Whenever I finish using the motor I unplug the fuel and run it dry, change the lower end oil yearly, plugs yearly, and inspect and replace hoses as required. Never had a serious problem. As a helicopter mechanic I know that preventive maintenance will help machines last infinately longer than those not maintained. A little money and time now will save a bundle later.

09-22-2005, 02:19 PM
I agree with the information previously stated. Just like cars it comes down to how well you maintain your equipment.

I've heard mixed answers regarding running the motor dry after each use while others claim you should never starve the motor until it runs out of fuel - which is correct?

09-22-2005, 03:12 PM
If you have a 4-stroke, it is a no-brainer. Run it dry each time. The carb has no real moving parts that need to be lubricated and fuel injectors will get lubrication as soon as the system is pressurized.

With 2-stroke engines, there is some concern that the rings and bearings will be "dry" upon startup and increased wear will result. But how may 2-strokes start up on the first pull or the instant the starter is keyed? My recommendation is to run any engine dry that is not going to be used for a week or longer.

That being said, my main engine does not have a detachable fuel line. So rather than manually draining 4 carbs, I use StaBil in the fuel at all times.

09-22-2005, 07:28 PM
Thanks Doc. I have both an oil-injected 2-stroke and a 4-stroke kicker and will follow your recommendation ;D

09-24-2005, 08:05 PM
My main engine like Doc's also doesn't have a detachable fuel line and I use stabil every time I put gas in the tank. It costs a little more to do that but I think the benefits are well worth it.
Waterdog ;D

09-25-2005, 06:30 PM
Where do you folks buy StaBil?

09-25-2005, 07:12 PM

09-26-2005, 09:55 AM
I recently purchased a new Merc. 40-4 stroke EFI and ask the Mech. at the dealership about running it dry (I had a 2-stroke 1965 mtr. that I always ran dry, and it's still a good engine) and he stated "Don't run the new Mtr. dry". Just put stablilizer in. This runs against my good judgement, but he is the Mech. and I'm not..

09-26-2005, 09:59 AM
Is there any benefit to adding StaBil to fuel that was already pumped into the tank about a month ago?

09-26-2005, 10:29 AM
Add stabilize after a month or so will stop further fuel degradation. Just before you use the engine, add a little high test fuel to the tank to restore the octane level.

Split_shot_1, ask your mechanic how the stabilizer is supposed to prevent gum formation in fuel system after it evaporates along with the residual fuel after a month or so. But overall I have to agree that the stabilizer seems to work OK for 4-strokes. I've not had to rebuild the carbs on my 90 after 7.5 years.

09-26-2005, 02:09 PM
I have a 1990 25 hp Yamaha that I have litterly run the dog snot out of and its still going strong. It has been used on the Delta running from one end to the other and even spent three years on Lake Mead where it would run for hours on end on that big lake. Now it spends a lot of time at trolling speeds and does great on that. The total hours on it? Not a clue but its a boat load (pun intended).

Good gas and regular maintance seems to have worked for me.