Yamaha 115 HP Smoke on start up

Mike MC

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May 30, 2011
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Yamaha 2005 115 HP with less than 200 hrs, when I start up I get a large amount of smoke and also have had a warning buzzer(which stops once the engine is running). Once started it runs fine,I can tell it's oil smoke because of the smell. I have also been plagued with a trim actuator leak that noone can fix I have had it worked on twice the fluid leaks out and then the pump will cavatate.

MikeMC
 

pine island fred

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Dec 20, 2002
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Re: Yamaha 115 HP Smoke on start up

2 stroke or 4? 2 stroke-- is of no concern, live with it. When you say the trim actuator, I assume you are talking about one of the 2 smaller cylinders not the tilt actuator. The top O ring in the piston also has a back up ring, probably teflon. Replace that also. If it is a 4 stroke, make sure the crankcase is not overfull ( making oil ). Around that time YAMAHA had a problem with the piston rings not being staggered, supposidly promoted the making oil problem. regards FRED
 

Mike MC

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Re: Yamaha 115 HP Smoke on start up

Fred, thanks for the reply. It is a Four Stroke, I had a complete tune up done a while back (at a local Yamaha approved shop) and it sems that is when it started the smoking? I have to take the boat out of the water to get it to the service center and the Trim/Tilt problem makes it dificult to get out of the water on the trailer. I have not checked to see if it's making oil or not? Do you know what the warning buzzer is when I do the first start of the day is? That is the only time it does it and of course that is when I get the most smoke is one the first start of the day? Some way I have to be getting oil in the combustion chamber-rings-valve guides or through the fuel?Thanks for your help. Mike
 

pine island fred

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Dec 20, 2002
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Re: Yamaha 115 HP Smoke on start up

Just went thru the repair manual to see if anything done during any HR. inspection or service could be related to an oil bypass problem. Could not find a thing. If the valves were over the combustion chamber, I could understand some oil running down the valve stem and being burned at start up. Even if there was a gallery in the head for oil to accumulate, yours is a very low time engine, valve guides should be like new. Inverted or radial engines can accumulate oil in the combustion chamber thru normal gravity draining down the cylinder wall. That is why in old timey movies you see guys pulling the props thru or pilots counting blades before they turn on the ignition.
Just a side note, as a young man I saw daily planes disappear in clouds of smoke when 4-- 28 cylinder engines were started in the morning. Was 40 weight oil too.
OK, enough of that! Your cylinders are not positioned for residual oil to run past the rings. Some might disagree but I would suggest you not be concerned with a bit of smoke at initial start up. Means the cylinders are lubricated. I think the less wrenches you put on a YAMAHA, the better off you are. Be satisified if the shop can repair your trim cylinder leak.
As for the warning buzzer, mine goes off and stays on momentarily also just like on my vehicles. Being in the sub tropics, I use 20W-50 in everything. Would say the most important thing to look for is to make sure the crankcase is not overfull. regards FRED
 

99yam40

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Sep 7, 2008
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8,851
Re: Yamaha 115 HP Smoke on start up

If you store the motor tilted all the way down then oil can leak past the rings and into the combustion chamber, tilt it up just slightly to were the oil will run into the crankcase instead and that should help
 

Mike MC

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May 30, 2011
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Re: Yamaha 115 HP Smoke on start up

Thanks I will try that when I get my tilt fixed and that does make sence because I had always store it in the lift tilted up as i was used to always being on a trailer then my tilt developed a leak and I got caught with the engine tilted up and had to do the by pass screw deal and decided to start leaving it down and that is when I started having the smaoke issues. Mike MC
 
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