99% sure it's your water pump seal. Had one go on my old bike. The oil was coming out the breather pipe like milk shake lol. Pretty straight forward and cheap fix mate if you do it your self.
You will have to order a water pump seal first if you have to keep using the bike. Then drain the oil and coolant. Remove right hand side crank cover after removing the water pump shield. You will also have to disconnect the two stroke lines and cable if you ain't running pre mix. You will see how the impaler dismantles. Get a small punch and knock the seal out using the hole provided this can be really hard like mines was. Use some threaded rod and two bolts and washers to draw the new seal in. Grease the impeller shaft and re assmeble.
Dont be temted to gouge it out with a screwdriver ect cause you will screw it up and it could leak even with a new seal . Has to be punched from the back.
My seal in that pic was still working lol. Was just replacing it in my total overhaul. I couldn't tell you 100% how to know if the seal was gone. I just cant think of a logical reason how water could make it into the gearbox. unless it was something totally stupid as coming in through the filler cap ect.
When the seal went on my NSR 125 and it was ooziing milkshake out the crankase breather. The coolant level wasnt even dropping much at all after I done an oil and coolant change without doing the seal but it was obvious the seal was knackered. I dont think it takes much water at all to make the oil milky.
I used an allen key that ended up bending I was trying to hit it so hard. Any thing that just fits through the hole you will see will be good as a punch. A good heat around the area with a blow torch wont do it any harm either. Mines was a nightmare getting it out.
Yeah for the £25 half hour labour it will save you alot of hassle just give them the clutch cover with the seal. They should be able to get the old one out and reassemble. I know I could and I ain't a professional lol. If they say £50 hours labour definatley do it yourself but for £25 it will save sone grief.
The usual good old chaps at yamaha give you a hole big enough for a tooth pick to be used as a drift lol. The hole for the impeller is the xact size as the hole in the crank. I got to know this operation well after swearing at it repeatedly for hours one afternoon lol.
The usual good old chaps at yamaha give you a hole big enough for a tooth pick to be used as a drift lol. The hole for the impeller is the xact size as the hole in the crank. I got to know this operation well after swearing at it repeatedly for hours one afternoon lol.
Looking at your pics above looks like you used a sledge hammer as a tool lol
FLOL If there had been one near I would have used it lol. I Punched clen through the hole with my allen key. At one stage my pliers were chewing at it like shark lol!!