Gas in Oil F250

[JZGrowler]

Thanks for all the great information I have learned a lot. The bad news for me is I'm 99% sure that my problem is not oil over filled, but actual gas in the oil

[rodbolt17]

sorry your scared.
that's why I am asking for a leak down test if the problem persists.

I hate to post it on the net.

but four stroke outboards of all makes suffer sumtin we aint never seeds befo00.

called piston ring gap alignment.

two stroke rings are pinned, they really should not rotate.

4 stroke rings are NOT pinned and occasionally they rotate.

its rare.
it happens.
but once the two compression rig end gaps line up,,,,, gas in the crankcase.
wont be any noticeable difference in engine pereformance.

compression test will NEVER find it.
a leak down test will.

this is assumiming the tech doing doing the test actually knows why.

more jameson I drink the worse I spell.

[boscoe99]

In aircraft piston engines the rings are supposed to rotate. All of the time. If they don't something is wrong.

I just assumed they are supposed to rotate in a marine four stroke motor.

Strange that with worn rings you can get oil flowing from the crank case to the combustion chamber while with making oil you get gasoline flowing from the combustion chamber to the crank case.

One might think that with there being so much unburned fuel moving from the combustion chamber to the crank case that the air/fuel mixture would be so poor (rich) as to barely support combustion, in which case the motor would run like crap. In reality it does not necessarily work this way.

It is a strange phenomenon for sure.

Certainly a test to determine if the rings are not seating well is in order.

[TownsendsFJR1300]

Somewhat related, I bought a slant 6 engine, Dodge (think it was a Duster) years ago (probably 20 years) with a MAJOR oil leakage. As in 3-4 quarts in 10 miles loss.

Ran fine, no smoke. Cleaned the engine compartment to find where it was originating from. Turns out engine oil is BLOWING OUT the dip stick tube. Yep, that much oil thru that little tube.

Pulled the engine, head, pistons, checked ring end gap.. About 1/4" gap!!!

The combustion pressure was apparently blowing past the compression rings, into the crankcase, then blowing the oil out the dip stick hole.

It was a pretty cheap car so I ended up simply honing and putting in new rings (which were just within spec).

Car ran great after that, brother in law drove it for years later without any leakage, burning, etc..

[rodbolt17]

yea that ole 225 slant six relied on a carb to move fuel.
the F250 is going to spray fuel even if the piston is missing.
if the ring gaps line up some fuel is going to be pushed past the gaps and into the crankcase before combustion occurs.

like I said its rare but it does happen.

[JZGrowler]

Rodbolt17, Thanks makes sense; leak down will tell a lot

TownsendsFJR1300, I should have called myself JZ R1200RT (-: my other passion

[TownsendsFJR1300]

TownsendsFJR1300, I should have called myself JZ R1200RT (-: my other passion

Yepper, that's my first passion, with two wheels...

Bet ya don't have one of these on your BM'er;






And that is a BMW lock assembly, originally made for a GS, that rekeys the same as your ignition switch..

[almetelo]

TownsendsFJR1300, I should have called myself JZ R1200RT (-: my other passion

Just big guns here... no room for my little pistol YAMAHA Xmax Howhever I'm very happy with it 2.8L for 100Km +/- 1Gal for 100Mi

A Tmax 530 would be nice (the R of the scooters hi hi hi) don´t want to aggrive your bikes lol

FJR1300 or Z750 would be my choice (yes, very diferent bikes I know...)
Maybe is something on the market much more interesting lately but bikes is no my passion, just a mean of transportation.

Good luck guys

[almetelo]

By the way....

At my work we have a Yamaha XT660 and a BMW GS650

A mix of both would be nice (the power of YAMAHA, and the Confort and security of the BMW)

[TownsendsFJR1300]

By the way....

At my work we have a Yamaha XT660 and a BMW GS650

A mix of both would be nice (the power of YAMAHA, and the Confort and security of the BMW)

Actually there is.. I sold the FJR years ago (first generation, the engine threw off way too much engine heat!).

My current bike, since 2009 (and sold everything else) is my Yamaha 07 FZ6.
600cc, inline 4, water/oil cooled, 100 HP, 14,000 red line, about 46 MPG. Its NOT a "lay down" bike, standard seating/position.

Built like a rock, maintainance is minimal. Low 11's in the 1/4 mile so its no slug either...

The FZ6;


My old, 2004 FJR with all the bags on (normally rode without them on);

[JZGrowler]

Ok now back to outboards

Looks like work will keep me from the boat until April. In April I will splash it to confirm a few things like make 100% sure it is Gas getting in the oil, then I will have a leak down test down, and report back.

My big ? that I hate to ask is what are my options if it fails the Leak down miserably ?

[99yam40]

The leak down will guide you to what the problem is, then address that

[rodbolt17]

options???
pay the maytag man

[rodbolt17]

dang them some cool bikes.
I do own and shoot some way cooler weapons

[JZGrowler]

Hey, I understand that I may be putting the Maytag repairman’s kids thought collage, but I’m just trying to understand my options if the rings are bad.

Is it practicable to take it apart, and put new pistons and rings in, or is better to put a rebuilt power head on it, or bite the bullet and re-power. Re-power seems sad since it runs so good, but being cheap is what got me hear in the first place.

I know this all to early, and I will definitely try Ring Free since every one suggests that, but I have never heard of it actually fixing anything but I have very little data so sure is worth a try. I have read about at least 5 different people with this issue, but none of them have come back on the web, and said this is what they did to fix it just what they were trying.

Thanks I know these are unfair questions with current data, but since im 1000 miles from the boat just trying to come up with a plan in my mind.

Thanks for all the input sure seems like leak down will give me a good idea of how big an issue this is. So I'm sure I will back in April with more questions when I have actual data not just guess.

Thanks JZGrowler or JZr1200RT (-: