White smoke at high revs F250

[Bajabuzz]

On the return portion of my last fishing trip the ocean was very calm so I was running the boat at high RPMs (5300) this is below WOT by about 400 rpm for this boat and load.
Engine is a 2005 F250 that has had the exhaust update done. Boat is a Parker 2310 WAC.
After about 5 minutes of running at this speed I noticed that the engine slowed about 300 rpm momentarily and then went back up to 5300. I did not look back at this point but just noticed the change. It happened again less than a minute later so I looked back and saw white smoke behind the boat, it was hanging in the air like oil smoke and not steam. I could see the beginning of it so it was not continious.
I immediately slowed the boat to 4000 rpm and smoke went away engine ran perfectly all the way back to harbor (5 miles). It ran fine at idle and no other symtoms showed up.
I havent done any diagnostics yet and wanted to get some opinions from this group about possible causes. I have the tools to do a compression test but dont know how to dissable ignition or fuel so it wont start during test.
Engine has 1250 hours currently and about 50 hours since an oil change. I bought the boat this year with 1,000 hours and it had just had a major service, exhaust housing update and inspection for purchase. I have not changed the water separator/fuel filter since I bought the boat.

Any comments or suggestions are appreciated.

Thanks you,

Charlie

[TownsendsFJR1300]

I'd do a leak down test on the engine, its much more in depth than a compression test

Also inspect your spark plugs as it sounds like one may have oil fouled momentarily....

[bajakeith]

boat motors

Buy your boat a REAL boat motor,,its been a TWO STROKE forever for a damn good reason......trying to ask a "prius" to be a semi is about the same gig as asking a POS four stroke to be a outboard...and btw I have 38/39 years as a pro mech in this biz......................eat cake,, wimpy,,wimpy four stroke...you can read it right here how probomatic a four stroke is !!

[TownsendsFJR1300]

Buy your boat a REAL boat motor,,its been a TWO STROKE forever for a damn good reason......trying to ask a "prius" to be a semi is about the same gig as asking a POS four stroke to be a outboard...and btw I have 38/39 years as a pro mech in this biz......................eat cake,, wimpy,,wimpy four stroke...you can read it right here how probomatic a four stroke is !!

That's not much of a help...

Curious, is your car/suv a two stroke??

[scofflaw]

2 strokes don't last and are junk ? You've had how many from new ?

Maybe you forgot to add the oil. Jackass statement for sure

[bajakeith]

Omg

If you, sir, think for a second that a four stroke is a better motor for a boat than a two stroke.......Uhh,, guess this is the first time as a master marine mechanic with about 40 years in the biz that I'm speechless...4 strokes were SHOVED down your wide open mouth...not to sound rude,,But,,"Get A Grip"

[TownsendsFJR1300]

The Op may or may not have an issue with his 4 stroke engine.

Wether a 4 stroke or 2 stroke is better for the water, in this thread is a MOOT point and USELESS to the OP, which is why we're supposedly here..

Noting to replace your engine, for the OP, is flat out silly and you know it, Master mechanic or John Q Public...


**Perhaps another thread to dispute the positives and negatives of each engine style would be more appropriate**.

[rodbolt17]

my guess is it's steam.
there are about 3 ways to burn oil.
leakage past the piston rings.
leakage past the intake valve stem seals.
excessive blow by gas burning in the intake track.
I would take an f250 Yamaha over any E-TEC,HPDI or verado any day of the week and twice on sunday.
the rest would simply be 10 to 15 yrs old.

best thing about it, they ALL fail.
I don't have maytag on my shirt.

[TownsendsFJR1300]

https://www.youtube.com/watch?v=ze_8LVnGNT0

[leveehog]

arrogance with no help

I don't think Bajakeith intends to be of any help.

[rodbolt17]

4 strokes,like E fuels were shoved down the taxpayer throat.
however that's what we have now.
my opinion of the E-TECH is about on par with a 3.3L HPDI.

my opinion on the F series VS is not to own one out of warrenty.
the 4 strokes did have some teething pains.
we wont even disscuss opti-pops.
same as catalysts on inboard and stern drive motors.
just more crap to go wrong. the cats on the Volvo are about 1100 each sitting on the counter.
outboards will have cats soon, look at the EX joint on the 2012 and up F115.
my guess is the F115 will be the test bed.

[zenoahphobic]

I don't think Bajakeith intends to be of any help.

Agreed, he appears to have a massive insecurity problem, because why does he constantly qualify everything with him being a master mechanic always with 4000 years in the business. He does not know how to present the merits of his argument without resorting to this, or he simply denigrates those that might have a different view.

[rodbolt17]

OR Baja may be like me, sometimes what I read,what my likker fuel fingers type and what I mean are different.

I do agree that the 4 stroke tech was a tad rushed for the US market.

I have seen 2 stroke 150 that ran 5000+ hours without a failure.

I still service 20+yr old 3.1L 2 strokes.

like I said before, I aint the maytag man.

[Nautical]

I wonder in reality, how many 4 stroke problems percent wise are related to fuel , including fuel pumps, as opposed to electrical, mechanical.

[boscoe99]

I wonder in reality, how many 4 stroke problems percent wise are related to fuel , including fuel pumps, as opposed to electrical, mechanical.

The majority of Yamaha problems, two stroke or four stroke, are fuel system related.

I believe that this is also the situation with the other brands as well.

Some real older carbureted Yamahas that ran on gasoline without ethanol almost never had fuel system problems. Some brand new carbureted Yamahas, ethanol or not, are problematic right out of the box. New EFI Yamahas can have so many components that it increases the probability of something going wrong. Couple that will lack of use and something bad is going to happen.

Fuel that sits unused for long periods of time, motors that sit unused for long periods of time, fuel systems that are vented to the atmosphere, the atmosphere around boats and motors being high in moisture content, ethanol contaminated gasoline in use that is attracted to water vapor, motors calibrated to run as lean as is possible, motors that have more fuel system components than a typical automotive system does, can lead to the perfect storm for a fuel system problem to occur.

Now I personally never had a fuel system problem of any kind. Carburetted motors, EFI two stroke or EFI four stroke. But when I was in the marine industry there were so many fuel problems that cropped up, across all models, that it made me almost want to quit boating. But I dealt in negatives. The millions of folks that don't have fuel problems go unnoticed as life is good for them. We never hear from them.