2003 90 hp 4 stroke yamaha smoking

I have a Yamaha 2003 90 hp four stroke that has started smoking on startup when tilted down to normal running position. It's quite a bit of oil smell smoke for about 15 seconds. It started about 2 years ago off and on and now happens every time the engine is cool/cold and tilted down and started. Otherwise it runs like a top. My mechanic thinks I might have a ring problem and we're talking about tearing it down. I'd hate to go thru that expense if it's not.
Any thoughts please?

Re: 2003 90 hp 4 stroke yamaha smoking

I think its mostly normal,especially if stored trimmed down.
a 10 minute leak down test will tell the tale BEFORE tearing anything down.
find a tech that READS tech bullitens and USES test equipment
best tool a tech owns is on their neck.
however some refuse to use it.

Re: 2003 90 hp 4 stroke yamaha smoking

Thanks for responding. I have a good tech but just in case could you tell me what the leak-down test is please. Also, just a thought, if there was a ring issue wouldn't a simple compression test tell?

Re: 2003 90 hp 4 stroke yamaha smoking

compression test really isnt worth much, a leak down test is faster and more accurate.
a leak down test simplified.
that cyl at top dead center on compression stroke is a sealed cylinder.
may not have a perfect seal.
thats what we wish to know.
so we inject a known air pressure into the cylinder and monitor how much make up air has to be injected to maintain that known pressure.
this is indicated as a percentage of leakage from the cylinder.
by listening at the oil fill,intake or exhaust we can tell where the leakage is.
less than 15% and your good to go.
next time you shut the engine down try trimming it up about half way, see if that helps as per the yamaha tech bulliten, or ask your tech for a copy of it.
we see it a lot with lift kept boats.
leave the engine trimmed down after shuttng it off and the spark plug end is now tilted downward, any oil behind the piston can make its way past a ring or ring end gap and is now in the combustion chamber, at the next start up the oil is burned off.
rather normal but ring seal is easily tested in about 10 minutes.
takes longer to get the hood and spark plugs out than the actual test.

Re: 2003 90 hp 4 stroke yamaha smoking

Thanks so much for the info....great advice!