Water in coolant reservoir Cannibal
I just got this quad changed oil and trans fluid which both looked good. No metal shavings no discoloration. I added new oil started it for a few minutes and then topped off the antifreeze. After running for a second I noticed what looked like oil in the reservoir. Proceeded to drain the coolant. Was green and clean looking until then end when it switched over to what felt like straight oil. Seen posts of coolant in oil but not vice versa. One thing I did notice was the coolant reservoir cap says oil. I thought maybe previous owner had put oil in there but i did ride quad for 30 minutes before doing fluids so even if done right before bringing it to me the oil should have atleast blended with the coolant i would have thought? Thanks ahead of time for any help.
If there is oil in the coolant it will churn it into a butter substance that will float to the top and leave a scum layer in the top of the tank. Now it is also possible that they were using evans waterless coolant which does not mix well with regular green coolant and will float to the top as well but will mix back in when running you just wont get the butter . Put the correct cap on the tank as its a pressurized system.