too much oil (gas in oil)

[nsullivan]

2000 100hp Yamaha 4 stroke. Less than 40 hrs.<br />oil level too high, strong smell of gas in oil. Dealer repaired, said it was thermostat, running too cool. Less than 5 hours since repair and oil is 1" over full on dipstick. When it was in shop another Mercury owner was in for same problem. Merc 4 stroke & Yamaha made by same company?? Anyone else experiencing?

 

[cobra 3.0]

Re: too much oil (gas in oil)

If your oil level is too high correct it. It is very bad to run an engine that has too much oil.

 

[shakespear]

Re: too much oil (gas in oil)

also bad to run engine on diluted oil does not lubricate<br />is fuel pump leaking into sump?

 

[SlowlySinking]

Re: too much oil (gas in oil)

Hi nsullivan, common problem with faulty thermostat, engine runs too cool and choke never fully releases, this puts excess gas in the cylinders which wipes the oil off the rings and the extra gas blows by into the crankcase which is why it checks overfull. Given that two sources pointed out the thermostat it gets easy to diagnose. On cars that tend to be used around town on many short trips the same thing happens, then you check the oil before a long trip, it looks full and it is, but it's oil and gas, you hit the highway, the hot engine burns off the gas from the oil and the engine runs low on oil and self destructs. Moral, always have an operational thermostat.

 

[flashback]

Re: too much oil (gas in oil)

is this an outboard? you may want to post it in the outboard forum............

 

[Spidybot]

Re: too much oil (gas in oil)

SlowlySinking got it.<br /><br />Get it fixed and replace the oil.

 

[JB]

Re: too much oil (gas in oil)

Moving to Yamaha Troubles.

 

[TMANS]

Re: too much oil (gas in oil)

I have a 2003 Mercury 115 4 stroke doing the same thing(Making Oil) as mercury calls it! See Mercury page. I have been told about the thermostat issue and that mercury is coming out with a 140 degree thermostat to correct the issue. The problem is that the manufacturer keeps back ordering the thermostat. I was originally told that these would be available in late July, then middle of August, then September 3rd. Now there saying 10/3/03.<br />I'm considering an attorney because my engine only has 21 hrs. on it and I feel like Mercury doesn't care. I've spoken with there customer service people and they have said that this is not a problem. It is a problem to me and I paid alot of money for a product that doesn't perform now. The dealer, where I purchased my engine has 3 more engines doing the same thing and one guy changed over to a 115 hp Opti-Max.The fuel in the crankcase can't be helping these engines!

 

[jim dozier]

Re: too much oil (gas in oil)

Do a search for this problem. There are 2 or 3 recent posts with the same problem. I don't know the final fix but there are others out there with the same problem.

 

[bludog]

Re: too much oil (gas in oil)

I have a 2004 Yamaha F115TXRC that is making oil and has poor fuel economy <br />(4MPG w 175 ScoutSportfish 1000lbs hull) <br />At 45 hours the dealer installed hotter plugs and changed the thermostat but now at 70 hours it is still making oil and fuel economy is even worse. It's back at the dealer for another <br />go at finding a solution. Anybody out there know a cure?

 

[TUCKER1]

Re: too much oil (gas in oil)

Listen I went through the same thing you are. I have a 2002 115 4 stroke efi mercury engine. My engine oil was a good inch above the hash marks. I was in the process of starting a class action law suit with Mercury, They first told me they would replace the T-STAT, That did not work, Then a bunch of other usless ideas that did not work, finally after they spent about $1700 of warrenty money They replaced the ECU (which finally fixed the problem) Remember Mercury and Yamas 4 strokes have the same exact power head. Unless they replace the ECU you are waisting your time.

 

[jerkin]

Re: too much oil (gas in oil)

What is the ECU? I'm having this same problem with a boat I just bought and it has me a little worried that the motor will blow up or something.<br /> Thanks Scott

 

[LOYD]

Re: too much oil (gas in oil)

WOULD ALL F115 CHECK OUT POST ON FIRST PAGE<br /> F115 MISSING

 

[LOYD]

Re: too much oil (gas in oil)

THAT IS WOULD ALL YAMAHA F115 OWNERS REPLY TO THE FIRST PAGE <br /><br /> F115 MISSING

 

[rodbolt]

Re: too much oil (gas in oil)

hello<br /> making oil is normally caused by running to cool. running over propped and excessive low speed operation and or improper breakin.<br />the t-stat problem can be compounded in some area due to cold water intake temps. so far I have never seen an engine damaged by it.<br /> however it has been an issue on some engines. if its EFI and has poor fuel economy check the vapor seperator as well as the pressure regulator. both can allow fuel into the crankcase. the low pressure fuel pumps are mechanical and like the ones used on automobiles. they dont fail often. the rubber diaphram is very thick.<br />not like a two stroke pump at all<br /> keep all your documentation and if you do call dont threaten or you will get the bottom of the stack. most large corperations have lawyers on the staff and your case may drag on for years<br />most the yamahas now run 140* t stats<br /> in my opinion its still to low but much higher and the minerals in raw water tend to form scale and will cause other problems<br /> most 4 strokes that run at least 30 min a trip at or near WOT dont have the make oil problems. the guy that never turns more than 3000 has them constantly.<br /> that motor is designed to run. it wont hurt it to cruise at 45-4900 RPM for 30 min to an hour each trip. <br /> make sure that F115 is propped so it can turn 6000 rpm. the rev limiter will grab it at about 6200 give or take.<br /> I have learned over the years to prop a 4 stroke so at medium loads and full liquid tanks the engine can hit the limiter.<br />helps keep them from lugging at midranges and making oil.

 

[LOYD]

Re: too much oil (gas in oil)

Rodbolt,<br /><br />they are now replacing the thermostat in my 2005 fs115. also, having a water fuel separator placed in-line. marine tech at the dealership says that this should fix the problem with the making oil issue and the loss of power{missing}. he said the faulty thermostat was causing the ecu control of the efi to allow more fuel to be delivered than is needed. any comments would be appreciated.

 

[rodbolt]

Re: too much oil (gas in oil)

could happen.<br /> but keep all documentation. anything that is done make sure its written down.

 

[garyN]

Re: too much oil (gas in oil)

Can't tell if anyone actually inspected the diaphram in the fuel pump. Really fine cracks can cause this problem in two ways<br /><br />First, it can physically allow the fuel to go into the crank,<br /><br />Second,a bad pump can keep the engine from hitting full WOT, and that can make oil.<br /><br />Really easy to inspect this, but dealers don't want to because, as I have been told, "if they do and it is not a problem then the warranty will not pay".<br /><br />My little four stroke made a lot of oil, due to the bad diaphram. Also, when we went to replace it a redesign was on the new pump. <br /><br />Check that diaphram.<br /><br />Gary