mattfish Posted January 13, 2006 Share Posted January 13, 2006 Hey i need some advice on my lower unit.I have a yamaha 70 horse power motor .I was changing the lower unit oil today and the oil came out like the color of coffee.the first few drops came out gray and the rest like the oil was fairly clean.I change it every fall when I stop fishing.The first year I had it I noticed that oil was leaking out of input hole.I changed it then added new seals on the screws.Now this year I see this.I wondering if this is normal or do I have water in the lower unit? If so what next?Would the water come out first pure or puddle separatley?Any and all advice would be appreciated. Quote Link to comment Share on other sites More sharing options...
cfruel Posted January 13, 2006 Share Posted January 13, 2006 When the lower unit oil comes out any color other then dark it is a problem and you have water in the lower unit. The reason the light comes out first is because it is heavier mixed with water. You need to have the lower unit serviced for water leaks and in most cases a new seal kit is not very expensive. I am not sure what the service fees would be if you deside to have it done. Cfruel Quote Link to comment Share on other sites More sharing options...
Yankee_Bassman Posted January 14, 2006 Share Posted January 14, 2006 How long since the motor ran? The regular clear (yellowish) gear oil should come out looking like oil; if it looks like a coffee milk shake, it's because its emulsified with the water. If it's been sitting awhile, some water will begin to settle, and come out first, but it will never completely separate. You probably have either a bad shift seal, or a bad prop shaft seal. I'm not familiar with the "guts" of Yammies, but they may also have seals in the water pump (impeller housing) base. A pressure test can be done on the gear housing to determine which. You can pick up the pressure pump plumbers use to check the integrity of gas and water lines at a home center for short money. You can get fiittings to reduce it to the opening in your gearcase. I think the pressure you pump to is about ten pounds, but I don't remember for sure. If you're handy, get a Seloc or Clymer manual; it will tell you how to do the pressure test, and walk you through the replacement steps. One of the easiest ways for a prop shaft seal to get trashed is from fishing line wrapping around the shaft behind the prop. If there's any there, or if you've found some recently, suspect that. The shift seal is the easier job to do, and while you're in there, you can replace your impeller kit, since you'll have that exposed to get to the shift seal. I did a shift seal on my 85 HP last year. Piece of cake, following the manual's disassembly/assembly directions. They also had a couple of "tricks of the trade" that saved a lot of aggravation. In any event, whether you do your own repairs or send it out, when you get it back, use it for a short while, pull the boat, and drain the oil. If the problem isn't cured, the oil will have water again. The aggravation of checking beats the heck out of the cost of replacing a set of gears in a lower unit. Quote Link to comment Share on other sites More sharing options...
mattfish Posted January 14, 2006 Author Share Posted January 14, 2006 sounds like i have some work to do .I origanally had problems with this motor in the carbs.out of the factory never even had 10 hours on it.yamaha extended the warranty on the motor so i'll let a dealer handle this for now .but i do have the service manual for the motor. kinda frustrated with this motor. like i said in the firstpost i noticed a leak out of the input srew not even after using it three times.thanks for the advice. Quote Link to comment Share on other sites More sharing options...
ernel Posted January 15, 2006 Share Posted January 15, 2006 If it was just a little bit (2-3 tsp) of the oil that came out grey, it was probably just metal shavings. All l/us have a little bit of metal in the oil when ever it is changed. This is from the gears meshing together. You don't have a filter like you do on your car, so it will all collect at the bottom of the foot after it has set for a little while, and will be the first thing that comes out. Water would not be grey at all it would have been off white to yellow. Hence the term milkshake. Before getting a new seal kit, just ask your boat mechanic to preform a vacume test on the lower unit. Most l/us should hold 8-10lbs as long as the vacume is still applied. Most will do the vacume test for a minimal charge, if not for free. Quote Link to comment Share on other sites More sharing options...
Bass_junky Posted January 21, 2006 Share Posted January 21, 2006 Just a thought....After long storage a lower unit can/will generate some condensation, this may be misleading some into thinking they have seal leaks.. Quote Link to comment Share on other sites More sharing options...
Ben Posted January 21, 2006 Share Posted January 21, 2006 If your running it hard, it will probably come out black. I change mine every six months and it's black everytime. Creamed coffee color is water. If the motor has been sitting for a while when you drain it, it's not uncommon to get that little bit of gray. That's where the metalic seddiment has settled to the bottom case and comes out first. Also, if you have a water leak problem, after it sits long enough to get the gray first, you will usually get a little water out when you drain it. Some of the water will separate from the oil and come out as water. Quote Link to comment Share on other sites More sharing options...
mattfish Posted January 21, 2006 Author Share Posted January 21, 2006 thanks guys I spoke with a yamaha dealer and described the situation that i have.he asked if any water was in the lower unit.i didnt see any come out.he also said that the oil will emulsify without water in the unit due to the churning oil.he suggested running the motor some morethen sticking something in the oil levelcheck to see what the color looks like. the motor sat for three months since its last use. Quote Link to comment Share on other sites More sharing options...
Yankee_Bassman Posted January 22, 2006 Share Posted January 22, 2006 You won't see the water come out separately; it will be emulsified with the oil. It turns the oil the coffee color you are describing. After sitting for three months, if there's water present, you MIGHT notice that the first bit of oil coming out the lower drain is slightly thinner than the oil on top, but the real clue is the coffee color. I'm not sure what the dealer means about oil "emulsifying" without water. "Emulsify" means two dissimilar liquids that usually stay separate when combined, will join together when vigorously mixed. Some will seperate again if left to stand long enough, like oil and vinegar shaken up in a salad dressing. Use a blender to mix the oil and vinegar, and it will take much longer to separate, and won't separate as dramatically as if only shaken by hand. The oil in your lower unit is unlikely to separate, because it has been so vigorously stirred by the action taking place in the lower gear housing. The dealer might mean that it will change color on its own, without water? It won't turn coffee colored, though. My .02 worth: if you can't find a friend who knows what to look for to check the oil for you after an outing or two on fresh oil, I'd get a pressure test done. It's dirt cheap compared to the cost of a new/rebuilt lower unit. Quote Link to comment Share on other sites More sharing options...
mattfish Posted January 24, 2006 Author Share Posted January 24, 2006 Yankee bassman Im taking your advice and going for the pressure test.thanks for the help. Quote Link to comment Share on other sites More sharing options...
Yankee_Bassman Posted January 24, 2006 Share Posted January 24, 2006 I'd be curious to know the outcome. YB Quote Link to comment Share on other sites More sharing options...
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