Yamaha Outboard Parts
Yamaha   Yamaha Outboard Parts
 
Yamaha Outboard Forum Yamaha Outboard Parts Discussion Forum Yamaha Outboard Parts Boat Parts Yamaha Outboard Forum Outboard Motor Parts Contact Us
Yamaha Parts
  #1 (permalink)  
Old 02-01-2012
Junior Member
 
Join Date: Mar 2010
Posts: 27
Default 2003 f115 burning oil

I have an f115 that seems to be burning oil. Under a heavy load I can see smoke off in the distance behind me while running. Also while running in yard there is a black spot on groung after running it and a thin black film on top water on my driveway while running. I do have to add oil regulary.I read in another post that prop size could affect this and I'm wondering how. I do think I need to go down a pitch as I only turn up about 5700 rpms. Any ideas or what else can be causing this. I also have a rough idle to and stalls eventually, down to about 600rpm but runs fine at any other rpm. Could this have anything to do with it? Thanks

Last edited by empty shell; 02-01-2012 at 11:35 AM.
Reply With Quote
  #2 (permalink)  
Old 02-01-2012
Senior Member
 
Join Date: Jan 2011
Posts: 227
Default

you may have a stuck open t-stat. this will keep the engine from reaching proper operating temp. you may also want to do a leak down test. I would get the engine checked out anytime you notice something not right, these motors can get real costly if you keep using it with something wrong. 5700 RPMs sounds about right.
Reply With Quote
  #3 (permalink)  
Old 02-01-2012
Member
 
Join Date: Dec 1969
Posts: 47
Default

I am not a mechanic but I recently had a powerhead replaced via warranty for a loss of oil issue on a 2006 F115 with 430 hours. 2 cylinders had water damage (though no fault of mine) and were scarred losing oil although I never saw smoke or a film. What about compression check? Have you pulled the plugs and inspected them. May have bad or misaligned rings on a cylinder or 2. A leak down test should also help diagnosis the issue. In my case I did a leakdown test and all appeared well. I did it at tdc only and the scarring was not evident at that point. The yamaha tech did it all the way through the pistons' travel and that is how they found the leak. As I understand it, that can be a dangerous test to run because the flywheel wants to turn past tdc. He had some mech's help him by holding the flywheel in place and gradually advanced it. Not sure how a diy'er would do that. If anyone has any advice I would love to hear it.

May also be bad valve seal on an exhaust valve. I believe a leakdown test my help find that as well.

Just my 2 cents and again I am not a mechanic. I may be way off base.
Reply With Quote
  #4 (permalink)  
Old 02-01-2012
Junior Member
 
Join Date: Mar 2010
Posts: 27
Default theromastat

I already replaced the thermostat, did nothing. Done a leakdown test but used a Harbor Freight tester, another words came out different everytime I tried it. My top plug seems to have a lot of black build up compared to the other three. I assume this is the problem cylinder.
Reply With Quote
  #5 (permalink)  
Old 02-01-2012
Senior Member
 
Join Date: Jan 2011
Posts: 227
Default

go ahead and pay a professional yamaha certified mechanic to do a leak down test. get a master tech if you can find one near you, yammy site has a list of them..be a good $100 to spend right here.
Reply With Quote
Reply

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On


All times are GMT -4. The time now is 09:01 PM.

Outboard Parts

Other Forums
Mercury Parts
Suzuki Parts
Evinrude Parts
Johnson Parts
Honda Parts

Copyright 2000 - 2014, Outdoor Network LLC