gas in oil

[<dj>]

Have a 115hp 4-stroke yamaha that I've used about a month. Noticed that my oil level was high after *****ing with motor for a couple of hours. changed the oil and took sample into dealer where purchased and they said this was normal. They said all 4-stroke motors would do this. I wasn't impressed with that answer. Has any one else had this problem and is it normal or a problem with Yamaha.

[<Yamaha support sucks>]

Well the dealer was correct to some extent. Gas in the engine oil of the Yamaha F115 is a very common problem. The problem caused both my F115 motors to wear out and there several other similar extreme cases similar. I have found the fuel filtration on these motors to be totally inadequate for EFI resulting in particles getting into the injectors. The injectors then leak fuel into the cylinders when the motor is turned off. The motors have another problem which is inadequate cook off especially when *****ing a lot. Yamaha's band aid fix is to fit a 10 micron prefilter/water trap before the motor. Proper automotive EFI and Honda outboard EFI have a final 5 micron pressure filter before the injector rail. I believe the filtration is not suitable for the purpose intended and the motor is not suitable for lots of *****ing. Please post your findings. Attached is some more reading for you:

http://www.fishingworld.com/Discussi...tID=0000008469
http://www.iboats.com/cgi-bin/ubb/ul...;f=30;t=003494
http://www.iboats.com/cgi-bin/ubb/ul...;f=30;t=003628
http://www.iboats.com/cgi-bin/ubb/ul...;f=30;t=004134
http://www.iboats.com/cgi-bin/ubb/ul...=003461#000006
http://www.iboats.com/cgi-bin/ubb/ul...=001021#000003
http://www.iboats.com/cgi-bin/ubb/ul...=001771#000003
http://www.iboats.com/cgi-bin/ubb/ul...=002640#000002
http://www.iboats.com/cgi-bin/ubb/ul...=002794#000001
http://www.iboats.com/cgi-bin/ubb/ul...;f=30;t=004148
http://www.iboats.com/cgi-bin/ubb/ul...=001221#000000
http://outdoorsbest.zeroforum.com/zerothread?id=146415
http://thehulltruth.net/forums/threa...d=9333&start=1
http://thehulltruth.net/forums/threa...=17930&start=1
http://thehulltruth.net/forums/threa...=19269&start=1
http://thehulltruth.net/forums/threa...27956&posts=12
http://thehulltruth.net/forums/threa...=19269&start=1
http://www.yamahaoutboardparts.com/c...c;f=1;t=000159
http://www.yamahaoutboardparts.com/c...=000171#000002
http://www.amsoil.com/articlespr/art...ard_motors.htm

[<dj>]

Am going to start keeping better track of when my outboard makes oil. Changed oil after the first time I noticed it. New motor had about 12 hours on it. It may be that the rings are not broke in yet so am taking a week off next week and will use it all week fishing with long trips in the boat. After I changed oil I took it out and had no increase in oil. Took it out again and it looks like I had about a pint increase. This is not a case of overfilling or reading the dipstick wrong.