05 F250 Excessive blow-by.... why?

[tunedportcj5]

Yep, I use it religiously, others call it my "snake oil"..

Anyway, is this product the same as the "dealer ONLY" stuff?:
ACC-CLEAN-D1-00 INTERNAL ENG CLNR 1Q



.

Yup, that's it...

[TownsendsFJR1300]

Yup, that's it...

Thank you!

Should you use it, please post back how exactly it's used and your results...

[99yam40]

read the directions before using.
not suppose to breath the fume/exhaust or have skin contact I think

[tunedportcj5]

read the directions before using.
not suppose to breath the fume/exhaust or have skin contact I think

I try not to make a habit of breathing exhaust fumes.. I'll report back on how it goes.

[99yam40]

I think rod posted it calls for a resperator and protective gloves .

plus you need a way to inject it into the fuel system

[robert graham]

Maybe/hopefully Rodbolt will offer his thoughts on this problem....his experience and knowledge on these motors is amazing!...

[tunedportcj5]

Maybe/hopefully Rodbolt will offer his thoughts on this problem....his experience and knowledge on these motors is amazing!...

Me too! Maybe he knows where the "easy" button is located?

[rodbolt17]

use a 1 gallon container and some hose.
mix about 20Z of YIES to 3 qts gas.
use two hoses one on the flush port one on the muffs.
run it through at about 1100-1200 RPM.
retest.

[tunedportcj5]

use a 1 gallon container and some hose.
mix about 20Z of YIES to 3 qts gas.
use two hoses one on the flush port one on the muffs.
run it through at about 1100-1200 RPM.
retest.

Is that 2 or 20oz?

[rodbolt17]

about 20 Oz. it wont idle well.
that's is why you need two water sources.
your going to have to run it 1100-1500.

[tunedportcj5]

I figured it had to be 20oz. I ran the 20oz/3qt mix yesterday for about 45mins fluctuating 1000-1500 with the occasional higher rev. It was a pretty uneventful process... no chunks of carbon flying out the exhaust, no foul odors, no smoke unless I revved the motor.

I only had time to test 1 of the cylinders before some major t-storms rolled through. It read the same as the pre-treatment @6% leakdown.

We are expecting more afternoon t-storms today, hopefully I can get the boat back in the water for some 5000+ rpm runs.

[tunedportcj5]

Unfortunately not any changes after the treatment. Leakdown and symptoms remain the same. Motor runs perfect though, ran 150+ miles this weekend... this is driving me crazy.

I still need to do the high rpm test and shut it down and check plugs.

[tunedportcj5]

I've seen this mentioned in some very old threads but can't find any more details on it... does this ring a bell to anyone?

At the Ft. Lauderdale Boat Show Yamaha had all their staff their, including several tech heads. I finally go to the head tech rep and learned the following important information for all 2005 250 4-stroke owners:

YAMAHA IS AWARE OF AN OIL BURN PROBLEM WITH A LIMITED RUN OF 2005 250 4-STROKE MOTORS. They have narrowed the problem down to run of motors with certain serial numbers. The problems has something to do with oil getting into the head unit when the motors are trimmed DOWN, resulting in it burning out through the prop-hub so you don’t see it. Yamaha has a “counter measure” kit for this problem which can be installed in about 10 minutes by Yamaha technicians.

I spoke with a well respected local Yamaha mechanic (who is just as stumped as the rest of us) who mentioned he had heard of a kit Yamaha had to fix this issue. It rerouted the crank breather tube to/though the oil fill cap and then back to the intake. Sounds similar to a "catch can" to me...

Has anyone heard of this kit before?

[tunedportcj5]

Just put 780 miles on the boat last week. Approx 40hrs of running time. About 400 of those miles were running 4500-4600rpm @40mph. There was no noticeable amount of oil burned - the oil level remained at the middle of the dipstick hash marks. Motors ran flawless...

However, problem still exists at 5000+ rpm... If I run the boat hard, the port motor still drops RPM and you'll see smoke rising up through the wake.

Aggravating!

[TownsendsFJR1300]

I'd be curious what spark plug(s) are black/wet with oil once you do a WOT, see smoke, then shut down "test".

For S&G's, as your issue is only at the higher RPM's, I'd see if there's much difference in the leak down test @100 PSI...

Also, I don't think posted, on each cylinder, when the leak down test was done, did you check(listen) for where the leakage was? IE, thru the intake, crankcase, etc?

I suspect probably into the crankcase and easily heard thru the oil filler hole..