90 HP Honda smokes SOMETIMES when fired up?

[joetheis]

This is on my buddies boat we use on Lake Ontario for salmon.
Here is the story.....................
It's a 2001 BF 90 HP Honda outboard, carbs not injected.
He has 10-30 Quick Silver semi synth. 10-30 oil in crank, done beginning of season, oil looks a bit dirty, but still feels good rubbing between fingers, (although I am not a outboard mechanic, 45 plus years of spinning wrenches for Chrysler 4 wheel land cruisers, so I'm not a zot).
At odd times with the motor DOWN ONLY, it'll start and looks like my 'rude 2 smoker.
If he tilts it up, nothing.........
I just noticed it Saturday.
We had done a high speed run to a new spot, shut it off, dropped the down riggers and when he fired it up, smoke! Maybe 30-40 seconds, a good puff.
He told me that it'll do it once in awhile.
We haven't run ANY test yet.
We're going to do a compression test, compression leak down, dump 10-40 oil in it also, (older Honda CRV engines have a history of oil use, recall and re-ring).
Will not smoke cold......
I THINK, he has a valve guide worn or a valve seal bad, (most likely bottom cyl.)
Thought? Jokes? Suggestions?
Joe

 

[Sea Rider]

Does Honda approves the use of semi or fully synthetic oils, or just mineral dino ones ? 4 strokes makes oil with use, the amount of oil in crankcase will rise furhter past max level.

Happy Boating

 

[joetheis]

I figure he's been using the same type/brand of oil for the years he's has it.
Quick Silver.
I asked him what brand and why not Honda outboard oil..... "Can't find it local", (he's also a, "Cheap Skate", he'll pinch 2 pennies til they squeal)!!
I keep telling him some stuff you can cheap out on, oil in a boat motor far, far, from shore isn't one of them!
Hey! It's his outboard!
I'm sure it can handle the blend or straight synth, as I've found if they can't first sign is always seal/gasket seep.
My humble thoughts are that synth. blends don't break down as fast as dino oil, as well as keep everything slick and spinning... but that just one old guys thoughts.
Next morning we checked the oil and it was a tad below the fill line, so we topped it off.
This motor does a TON of idle trolling.
I tried to tell him it hard(er) on a motor at idle..... oil psi is lower, the water is flowing as hard to cool it as well as in the upper ranges.
I've read that oil get in the air box and that oil level should be a a skinny bit low, as these motors WILL huff oil in the down position through the rings.
I talked him into 10-40 oil, (a bit heavier) and filter.
do some test...
I was hoping this was a common problem with these Honda motors with some hours on them, and I be able (as always on this site), pointed in the right direction!
Joe
You know, my sailboat never fails to start and run!