Yamaha C90 Smoking After Impact With Log

[PogeyBait]

Hello All. At about 2 mph my outboard hit a log. Didn't seem too hard but definitely solid. After about 10 minutes, I noticed grayish smoke at low mph. Didn't smoke at all before impact. Ran strong as ever for about a 4 mile ride to dock at around 15 mph. No visual damage at all when I pulled it out of the water. Any ideas?

 

[99yam40]

my crystal ball is not functioning properly right now, so you will have to do some more trouble shooting/inspections

 

[robert graham]

I run a C90 and what you describe may be some fear/paranoia about hitting that log....2mph ain't very fast. Maybe take the boat for a wide open throttle run down the river and check/ look for smoke, vibration, etc. Check your prop, skeg, lower unit for any damage.....

 

[PogeyBait]

Thank you for your reply. Sorry to hear about the crystal ball malfunction. Perhaps, while your having it fixed they can check on your your manners function. Maybe you could recommend some of the aforementioned trouble shooting inspections. Thanks in advance for your anticipated generosity. I am grateful.

 

[PogeyBait]

Thanks Mr. Graham. Unfortunately, I really didnt think twice about the hitting of the log other than I like to treat my things nicely and at most shuddered for a second or two thinking about it. However, approximately 10 minutes later, both my wife and I noticed it while idling and at very low speed. Actually, if it were only a little smoke, I really wouldnt think twice but it was too much to be just nothing. At least at this point. Unfortunately, it was pouring rain all the way in and has been all day. I will continue with my inspection and troubleshooting when the rain relents. Thanks for the positive thinking though!

 

[99yam40]

hitting a log should not have anything to do with a premixed Yamaha outboard motor starting to smoke at low RPM or high RPM.
the fuel mix going into and being burned by the motor should have the same amount of oil it had before.

water getting into the combustion chambers will cause steam/fog out of the exhaust. maybe that is what you were seeing

 

[PogeyBait]

Thanks 99, I was wondering if condensation in my tank could overpower my fuel water separator and maybe cause it. Thanks again for your response.

 

[robert graham]

Check that Primestart unit on carb to be sure the red lever is in the "normal" position....if it was in the "on" position or malfunctioning to stay on it could cause a rich mixture causing smoking.....also check fuel pump for bad diaphragm which could also cause rich mixture/smoking. Since it's a premix motor then a rich mixture could be the cause of the smoking, rather than excessive oiling...