Our 2014, Yamaha 300 UCA has at times gotten some water ('milky' oil) in the lower unit lube/oiI. I've seen it a couple times over the years, when I've changed the L/U oil. So I started changing it at 50 hours instead of 100 hours. (there is about 950 hours on the motor now). When I started changing it at 50 hours, the oil looked real good; no 'milky' oil. A couple time when I changed it around 100 hours, it looked 'milky'; as shown in this video;
I've pulled the prop a number of times. Only once was there a tiny, few pieces of fishing line, easily removed. All other times, nothing; no fishing line......
I've read that this particular Yamaha engine has had issue with the seals down there in the L/U, and that a little water in the L/U oil is expected, and is not an issue. The Yamaha manual even states 10% is 'normal' and not an issue (I don't like ANY water leaked there, and how would I determine 10% !) .... I would love to hear the opinion and expertise from the ClassisParker gurus.... I troll a lot around 7-8 mph. Does running at low rpm cause the L/U seals not to 'seat' properly. Even when I troll for hours, I still run it at 4300-4400 rpms for 45 - 60 minutes on the way home.... Then to 5000+ for a few minutes.... I'm wondering if trolling at 7-8 mph is not good for a 300 Yamaha?
I've pulled the prop a number of times. Only once was there a tiny, few pieces of fishing line, easily removed. All other times, nothing; no fishing line......
I've read that this particular Yamaha engine has had issue with the seals down there in the L/U, and that a little water in the L/U oil is expected, and is not an issue. The Yamaha manual even states 10% is 'normal' and not an issue (I don't like ANY water leaked there, and how would I determine 10% !) .... I would love to hear the opinion and expertise from the ClassisParker gurus.... I troll a lot around 7-8 mph. Does running at low rpm cause the L/U seals not to 'seat' properly. Even when I troll for hours, I still run it at 4300-4400 rpms for 45 - 60 minutes on the way home.... Then to 5000+ for a few minutes.... I'm wondering if trolling at 7-8 mph is not good for a 300 Yamaha?