# Running WOT for long extended periods of time



## joebucko

I normally run my Mercury 4stroke WOT depending on water conditions.


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## Capnredfish

Almost never.


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## lemaymiami

If you're depending on your motor day in and day (and plan on paying your bills with it....) you'll only run that motor wide open for a few minutes at the end of every day.... Guys that use their motors for fun can do as they please....


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## el9surf

Almost never due to wear and tear. Same reason I don't drive my car like I stole it.


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## mtoddsolomon

I did on my last boat all the time, and never had any issues. If the conditions allow, why not? I've got a couple of guide buddies that run their boats WOT almost all the time and get crazy amounts of trouble free hours on their boats.


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## ceejkay

i run my 25 2 stroke wot as much as possible. days that i hit the intercoastal where i only get up on plane for a short while if any the motor smokes like hell and feels like it doest run as smooth


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## crboggs

My 21 year old Merc 2 stroke 115 has two speeds...idle or WOT...


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## BMPDave2013

Run my 2014 40hp etec at 4500 to 5000 most of the time. No hurry to get anywhere. WOT sometimes just for fun but only for a short time.


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## TylertheTrout2

I gotta agree with Capt. Bob...I myself can't afford to replace/rebuild anything at the drop of a hat so I just run my 99' Merc 50 two-stroke (god only knows how many hours she has) enough to get on plane and cruise comfortably..also don't mind savin a few bucks on fuel...all personal preference I guess!! Cheers.


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## firecat1981

I usually run just under WOT, maybe 5000-5200rpm. As long as you are up on your maintenance, especially your cooling system, then things should be ok.


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## GatorFan321

I run mine and always have my previous motors (including mud motors) at idle or wide open. Nothing in between. I also have never had to fix anything on any boat motor Ive ever had. The same way when i used to ride dirt bikes. I rode them as fast and hard as possible. There are rev limiters for a reason. They keep the motor from reving to dangerous RPMs. Even in my new motors manual it says its ok to run it wide open 100% of the time after break in period.


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## WhiteDog70810

I seem to recall hearing that 2-strokes can run at WOT by design.

I don't know where 4-strokes are meant to run.

I am kinda waiting for Cutrunner to weigh in on this.

Nate


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## permitchaser

I usually run about 30 mph or 5,000 rpms but occasionally I'll let her fly


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## Sandalous

I've always heard that 4strokes are more suited for long periods of wide open throttle. With any engine, you are going to lose a lot of range running at WOT. I also come from the school of overpowering the boat in order to cruise at lower RPMs.

If I never had to worry about being stranded 40+ miles from the ramp with no communication or way to get home, or running with a lightning storm on my ass for 20 miles, I would probably run my engine WOT all the time.


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## permitchaser

IMHO. People who run WO all the time are under powered


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## GatorFan321

permitchaser said:


> IMHO. People who run WO all the time are under powered


I have run every boat ive ever had wide open unless in a zone every time i ran them and they have always been over powered according to the USCG decal or equal to the USCG highest hp rating. On a lot of micro skiffs we are limited to small hp motors so if we can only have a 25 or 30 then we aren't breaking any speed records running wot. If i had a bass boat with a 300 on it I probably wouldn't run it 73mph all the time. Shit would be fun though.


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## CaptainRob

Hardly ever run mine at WOT. If crossing a lot of open water, there are only so many nice days where WOT is even possible. For me, most of the time I am somewhere between 3800 and 4200 rpms. Allows me to slow down and enjoy the view...


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## RunningOnEmpty

High rpm's will reduce a motors life expectancy.


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## el9surf

RunningOnEmpty said:


> High rpm's will reduce a motors life expectancy.


I thought this was especially true of 4 strokes. I always thought 2 stroked were meant to be run at high rpms. 2 strokes definitely have a shorter life span than a comparable 4 stroke if maintained properly.


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## RunningOnEmpty

el9surf said:


> I thought this was especially true of 4 strokes. I always thought 2 stroked were meant to be run at high rpms. 2 strokes definitely have a shorter life span than a comparable 4 stroke if maintained properly.


Stress goes up with rpm's in all motors.


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## Whiskey Angler

RunningOnEmpty said:


> Stress goes up with rpm's in all motors.


True, which could have a more detrimental impact on 4-strokes as they incorporate valve-trains which are dependent on relatively tight tolerances...tolerances that are affected by wear. 

Nonetheless, manufacturers consider these things (an optimistic assumption) and account for them in design and warranty.


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## RunningOnEmpty

Whiskey Angler said:


> True, which could have a more detrimental impact on 4-strokes as they incorporate valve-trains which are dependent on relatively tight tolerances...tolerances that are affected by wear.
> 
> Nonetheless, manufacturers consider these things (an optimistic assumption) and account for them in design and warranty.


The 4 stroke outboards use solid lifters that require service to maintain proper valve clearance. 6000 rpm's isn't a big deal if the motor is properly designed to handle it. Honda has a indy motor that turns around 21k rpm's!


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## mtoddsolomon

I've still got an old Honda CRF450r from when I raced when I was younger. The thing has been run wide open since the day I picked it up, raced for 3 seasons, back up bike for 2, and messed around with for the past 8 years or so. It's been maintained and serviced regularly and still starts on the first or second kick. With the exception of my daily drivers, because of speed limits, I'll run almost everything wide open.


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## jonrconner

Small displacement engines like we have in current outboards run at comparatively tame rpms and produce very tame specific hp when compared to, for instance, sport bike motors which peak out at twice the rpms and four times the hp per liter, this makes outboards look kind of agricultural in character. You can run them at full throttle all day for as long as you like, the only downside is you'll burn twice as much fuel to go maybe twenty five percent faster and you probably should change your oil a little more often. 
Stress and wear are related to reciprocating mass, again outboards have very small displacement per cylinder compared to car and truck motors which run as high as close to a liter per cylinder and still will turn 5000-6000 rpms.
Just a little perspective.
JC


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## Net 30

RunningOnEmpty said:


> The 4 stroke outboards use solid lifters that require service to maintain proper valve clearance. 6000 rpm's isn't a big deal if the motor is properly designed to handle it. Honda has a indy motor that turns around 21k rpm's!


That's a F1 Engine! INDY cars are for pussies  

Even with the Honda Engine, McLaren can't compete with Mercedes and Ferrari


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## csnaspuck

Not sure if anyone mentioned this but a certified Mercury mechanic once told me that running at the same RPM will create a harmonic vibration that can cause issues. So when I am running every 30 seconds ill bump the throttle up or down 100 RPMs. Not sure this is really true but in theory it makes sense.


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## devrep

mtoddsolomon said:


> I've still got an old Honda CRF450r from when I raced when I was younger. The thing has been run wide open since the day I picked it up, raced for 3 seasons, back up bike for 2, and messed around with for the past 8 years or so. It's been maintained and serviced regularly and still starts on the first or second kick. With the exception of my daily drivers, because of speed limits, I'll run almost everything wide open.


I raced MX for years and still have 7 mx bikes in my garage including a CR500AF. I only do off road now. If you're riding a 450f wide open all the time you must be an ex national pro.


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## jfboothe

devrep said:


> I raced MX for years and still have 7 mx bikes in my garage including a CR500AF. I only do off road now. If you're riding a 450f wide open all the time you must be an ex national pro.


Or you never got out of first gear...


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## firecat1981

Dirt bikes have more then one gear?


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## KnotHome

el9surf said:


> \] 2 strokes definitely have a shorter life span than a comparable 4 stroke if maintained properly.


I have yet to see real world evidence of this, especially in the commercial industry.

Outboards aren't car engines. There's no transmission, so it's meant to be run at high RPMs. Running WOT is to be expected based on the limitations of small boats. I don't like to do it on my current boat because of significant fuel savings and I'm usually busy looking around for signs of fish, but my old skiff with a 15 horse didn't have much choice.


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## mtoddsolomon

Tough crowd. Not a national pro but definitely found my way out of first.


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## el9surf

Seems like there are different schools of thought. I never really worried about running wot with my two strokes was always told they were meant to run like that. I have always babied my 4 strokes, usually run them around 3/4, usually wot for a minute or two each trip. I figured with the more complex design and moving parts there was more to stress and break, or at least that's what I have heard. Would be interested to hear from a motor tech.


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## Whiskey Angler

This is kind of on topic... has anyone ever seen an Merc. Optimax compressor let go running WOT at 6K rpm's? I have....it's AWESOME!


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## GatorFan321

csnaspuck said:


> Not sure if anyone mentioned this but a certified Mercury mechanic once told me that running at the same RPM will create a harmonic vibration that can cause issues. So when I am running every 30 seconds ill bump the throttle up or down 100 RPMs. Not sure this is really true but in theory it makes sense.





Whiskey Angler said:


> This is kind of on topic... has anyone ever seen an Merc. Optimax compressor let go running WOT at 6K rpm's? I have....it's AWESOME!



Thats why people should buy Honda or Suzuki outboards.


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## Jim Lenfest

crboggs said:


> My 21 year old Merc 2 stroke 115 has two speeds...idle or WOT...


Same as mine, a two speed motor.


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## Jim Lenfest

Whiskey Angler said:


> This is kind of on topic... has anyone ever seen an Merc. Optimax compressor let go running WOT at 6K rpm's? I have....it's AWESOME!


Sadly, the Mercury dealer in my town nicknamed renamed the Optimax to Optijunk. He threw in the towel on the Mercs and started selling Yamaha full time. I still run the old 2 stroke mercs that you mix your own oil and gas, but suppose one day, I will be buying a Yamaha from him when I have no other choice in town.


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## Jim Lenfest

Advice from my former Mercury, currently Yamaha dealer. First, make sure you have the correct prop to run in the correct rpm range for your motor. He said 2 strokes run great at WOT for extended periods while 4 strokes should only be run that way for short periods. As above someone said, kind of like a car. The 4 strokes have a lot more moving parts that can fail under stress. He also recommends stopping the 2 stroke with the choke on the last stop of the day or after the fresh water flush. This, he says, loads the cylinders with oil for the storage.


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## fjmaverick

Ive heard many times four strokes should be run at wot at least once a trip for a few minutes to blow out any carbon build up.


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## swaddict

I run my Yamaha 2 stroke wide open most of the time, now my Merc performs much better when I'm running in the upper rpm range of that motor


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## "Scott"

Whiskey Angler said:


> This is kind of on topic... has anyone ever seen an Merc. Optimax compressor let go running WOT at 6K rpm's? I have....it's AWESOME!


Any pics or a video...?


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## "Scott"

Jim Lenfest said:


> Advice from my former Mercury, currently Yamaha dealer. First, make sure you have the correct prop to run in the correct rpm range for your motor. He said 2 strokes run great at WOT for extended periods while 4 strokes should only be run that way for short periods. As above someone said, kind of like a car. The 4 strokes have a lot more moving parts that can fail under stress. He also recommends stopping the 2 stroke with the choke on the last stop of the day or after the fresh water flush. This, he says, loads the cylinders with oil for the storage.


That's a great tip that I have never heard before.... Using the choke to stop the motor at the end of the day. Will definitely try that as have just picked up a new 2 stroke Yamaha 15hp and am about to run it in... Have heard of pulling the fuel hose off and letting them run dry so fuel doesn't evaporate and leave the oil to gum up the carburettor... But now you mention it, this would mean perhaps leaving less oil in the cylinders... Thanks for the suggestion!! Much appreciated...


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## Vertigo

A motor has only so many revs in it. You can take them out as fast or as slow as you want.


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## sjrobin

Vertigo is correct. Most of us don't spend enough time on the water to put 2000 hours on an engine or we don't stay on maintenance schedule and destroy the engine. I have 110 hours on a F60 that I bought in August 2015. If I live long enough I might put 2000 on it. Most people that I have known with older OB's do not operate them at WOT. Given that you don't overheat the head, carbon deposits accelerate wear by inhibiting heat transfer, especially in two cycles. De-carbon once a year. OB mechanics looking for work love most tunnel hull boats and operators. Base line engine temps run higher=reduced life.


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## "Scott"

sjrobin said:


> Vertigo is correct. Most of us don't spend enough time on the water to put 2000 hours on an engine or we don't stay on maintenance schedule and destroy the engine. I have 110 hours on a F60 that I bought in August 2015. If I live long enough I might put 2000 on it. Most people that I have known with older OB's do not operate them at WOT. Given that you don't overheat the head, carbon deposits accelerate wear by inhibiting heat transfer, especially in two cycles. De-carbon once a year. OB mechanics looking for work love most tunnel hull boats and operators. Base line engine temps run higher=reduced life.


Thanks, good advice, but have never de-carboned any of outboards (all two strokes 15-90hp). Are you talking about using something like seafoam? 
Regards
Scott


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## Jim Lenfest

crboggs said:


> My 21 year old Merc 2 stroke 115 has two speeds...idle or WOT...


Mine are run the same, two speeds. But if I owned a 4 stroke, I would consider a little less than WOT.


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## Smackdaddy53

Let her eat! If they weren't meant to run WOT it wouldn't be called WOT. I know most motor's redline is actually a few hundred RPM higher than the WOT printed on the serial number sticker.


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## Tx_Whipray




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## Smackdaddy53

Tx_Whipray said:


>


ELEVEN!!!


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## devrep

I run wide open a lot. NFG.


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## Adam w

Wide open is how mercury tests their motors. They have a plant in my town and I've known a few people who have worked there. Wot for 8 hour shifts


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## Smackdaddy53

Adam w said:


> Wide open is how mercury tests their motors. They have a plant in my town and I've known a few people who have worked there. Wot for 8 hour shifts


I think my Merc 90 ran 8 hours the whole time I had it, POS was broken down or not running right from day one.


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## Guest

After break in, run them all how you see fit. Trust me though, the 4 strokes like the rpms. I’ve seen people try to baby them from new and rings never seat.


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## RunningOnEmpty

My boats old owner warned me about fouled spark plugs. He said he never ran any faster than 35 mph. After one year the motor hasn't had anymore plug fouling and it gets plenty of WOT time now in the mid 50's. I think it's good to blow them out often.


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## Snoball

fjmaverick said:


> Ive heard many times four strokes should be run at wot at least once a trip for a few minutes to blow out any carbon build up.



What my dad always told my mom when he started getting a little sporty and she started bitching. I use it on my wife too!


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