Yamaha 115 4s water in oil?

[xo4001]

Hi guys,

As the subject say
Recently bought 2 F115 from 2002
Run them on the hose run good
Test run them on the water and run good wot 5800 at least one tach I could read
The other one was so sunburned could not read them
After taking possession of the motors did some running around on low rpm because of ruff weather
Checking oil level and found milky oil
Did some research and a cold engine running could cause this Pulled the thermostat
Found stuck open will look tomorrow for a new one
also bought new tacho meters and changed them out found that the one I could not read before is not coming on!
when I change the new meters it will come on so there is something wrong in the wiring
Is there some one who has a wiring schematic that will be a great help to try to find my problem
Also installed a new fuel management meter from Yamaha and is also not coming on
The schematic that supplied is very limited hope fully there is a better one on CA
Any help is much appreciated
Thanks
Martin

[slvrlng]

Wow Martin! Hopefully someone with a lot more experience with these systems will chime in soon. Myself I have a hard time understanding how water can get into the oil just from a thermostat not working. Did you have the midsections scoped before purchase. I know 225s of that era have a corrosion issue in the dry part of the exhaust. This causes the oil pan to rust out in time.

http://www.boatus.com/magazine/2012/oct ... laints.asp

[bondobill]

I have had gas in the oil on my Yamaha 4 stroke kicker motors....I have had 4 of them over the years..... from running them with a stuck open thermostat, but never water.
I can understand how water would get in the oil because of corrosion.
If you want to see what corrosion can do to a Yamaha 4 stroke take a look at the photos I had posted about my kicker motor upper casing and oil tank.

Bill

[xo4001]

Ok had the electrical issues solved
All the gauges are working now
It took about 5 minutes to connect the wires for someone who know what he is doing with no schematic

Waiting for my thermostats to come in hopefully next week
Lewis thanks for the link very informative
And of course I did not check that out a lesson learned for the future

Bill I see your pictures that get me scared
I looked inside where the thermostats go and look very clean but can only see a little bit in this stage I hope for the best for now

[slvrlng]

Hey Martin, that is good news so far! We have a brand new member that I solicited to join to answer questions on Yamaha issues since we have so many members with them. He goes by SIM and is a vendor for Yamaha and he really knows his stuff on the 4 stroke and 2 strokes. I am sure he will chime in tomorrow with much more info and questions for you so check back when he chimes in. He is aware of this thread and was waiting approval to join our merry clan.

Here is a link to their sub forum on THT just so you see who they are and what he is able to answer.

http://www.thehulltruth.com/shipyard-is ... -parts-22/

[xo4001]

Wow love this site
Thanks Lewis

[seabob4]

And that would be Andy Munao at SIM Yamaha in Washington Island WI.  If you ever order parts from him (I do), you'll be dealing with his wonderful wife Lisa...

[icemanbryan]

And that would be Andy Munao at SIM Yamaha in Washington Island WI.  If you ever order parts from him (I do), you'll be dealing with his wonderful wife Lisa...

Andy is awesome, really knows his stuff.
I bought my Binnacle from him and both of my replacement gauges last year.

I just purchased my seals for the TNT unit from the website.
I like the site he has because it shows the needed items as well as a tool you may need.

[SIM]

Hi guys,

As the subject say
Recently bought 2 F115 from 2002
Run them on the hose run good
Test run them on the water and run good wot 5800 at least one tach I could read
The other one was so sunburned could not read them
After taking possession of the motors did some running around on low rpm because of ruff weather
Checking oil level and found milky oil
Did some research and a cold engine running could cause this Pulled the thermostat
Found stuck open will look tomorrow for a new one
also bought new tacho meters and changed them out found that the one I could not read before is not coming on!
when I change the new meters it will come on so there is something wrong in the wiring
Is there some one who has a wiring schematic that will be a great help to try to find my problem
Also installed a new fuel management meter from Yamaha and is also not coming on
The schematic that supplied is very limited hope fully there is a better one on CA
Any help is much appreciated
Thanks
Martin

Hi Martin,

I would start by making sure you check the easy stuff. The drain plug for the oil pan has a washer on it. Make sure its there.

If it was, then I would drop the lower unit and check up in the exhaust passage for corrosion. If you see much corrosion there, I would probably remove the powerhead and check the area underneath it for corrosion. You will know for sure once the powerhead is removed if that's the problem.

I assume it runs well otherwise?

Andy

[xo4001]

Hi guys,

As the subject say
Recently bought 2 F115 from 2002
Run them on the hose run good
Test run them on the water and run good wot 5800 at least one tach I could read
The other one was so sunburned could not read them
After taking possession of the motors did some running around on low rpm because of ruff weather
Checking oil level and found milky oil
Did some research and a cold engine running could cause this Pulled the thermostat
Found stuck open will look tomorrow for a new one
also bought new tacho meters and changed them out found that the one I could not read before is not coming on!
when I change the new meters it will come on so there is something wrong in the wiring
Is there some one who has a wiring schematic that will be a great help to try to find my problem
Also installed a new fuel management meter from Yamaha and is also not coming on
The schematic that supplied is very limited hope fully there is a better one on CA
Any help is much appreciated
Thanks
Martin

Hi Martin,

I would start by making sure you check the easy stuff. The drain plug for the oil pan has a washer on it. Make sure its there.

If it was, then I would drop the lower unit and check up in the exhaust passage for corrosion. If you see much corrosion there, I would probably remove the powerhead and check the area underneath it for corrosion. You will know for sure once the powerhead is removed if that's the problem.

I assume it runs well otherwise?

Andy

Hi Andy,
Welcome to this site
Thanks for your reply
You think that the thermostat has no deal with this?
Where you think that the water in coming in?
Is this the engine base pan/oil pan or would it be where the power head is bolted down
I'm mechanically inclined but have no experience with this motor
Thanks
Best
Martin

[Mike 139]

I've just dealt with this issue the past couple weeks...... 03 F115 had 288 hours on it when I purchased it. Ran perfect, smooth, pushing an Edgewater 185 @ 40 MPH on the GPS.

After 7 hours/110 miles, found milky oil and did comp test,170,170,170,155 on number 4 and plug wet with water. Did leakdown test and #4 @30 %.

Pulled powerhead and removed cylinderhead and found water intrusion from corroded jacket,#4, bottom cylinder. Block corroded almost thru to exhaust ports.

I'm currently at 2.5 hours into the break-in of NEW head/block.......A stuck t-stat can "make oil" ,but more likely ,the low pressure fuel pump has a leaky diagphram putting gas into the motor.  You can easily check by pulling the pump off the valve cover and pushing in the plunger while making sure the primer bulb is firm and the lines connected....if you get fuel coming off the plunger, it's leaking.

New motor a much darker gray and has additional external water lines going to the cylinders, Yamaha DOES have known corrosion issues and has made recent changes to their coatings. My Tech told me this is the 3rd F115 with the same issues   in recent months and his shop is littered with exhaust housings/plates from 225's.

I hope yours is just a head gasket......New heads/Block assemblies from Yamaha are NOT cheap.


Your motor is an in-line double overhead cam 4 cylinder,4 valves per cylinder, modified Ford Focus engine with flat tappets requiring oil with a ZDDP package. Motor is vertically  mounted to center section,sits on top of oil pump and has a split oil pan that has water and exhaust passages running thru the center of it.

[xo4001]

Hi Mike,
Thanks for your feedback
This will not give me much hope but it is what it is I guess
can you PM me what the cost is for a new power head
Will prepare myself mentally for this job
Best Martin

[bondobill]

Yamaha DOES have known corrosion issues and has made recent changes to their coatings.

I heard the same thing from Yamaha about  new alloys and coatings back in 94 when my 1991 4 stroke rotted out in the exhaust casing.
They are getting better tho...my 2000 model lasted 12 years before it rotted away.  

Oh well, there ain't no money to be made making a light bulb that will last forever either.  
But you know what..I probably will be buying another new Yamaha kicker this weekend, they just run so damn nice and besides at my age......
this next one should outlive me.  

Bill

[RickK]

Not since you quit smoking - you'll get a few more years out of them lungs now.  I smoked for 30+ years and a checkup the other day said lungs sounded perfect after 10 years of quitting.
As I said - battle it 3 seconds at a time - you'll be fine.

[bondobill]

Thanks Rick  
What's ya thinking ?
Maybe I should buy a Merc ??  

 
 Bill
 :pirat: