How much grease is normal to come out the end of the shaft by the prop? On a 12 hp copperhead. It's not much and just got the motor so I wanted to make sure before I run it to long or if I needed to replace the seals in it. I know if a lot of grease is coming out water will get in. I've had other mud motors that barely leaked any but just checking.

Hmm... I would call or email Copperhead and ask them to be sure, but I have not ever had grease coming out on any of my Copperheads and I usually give them some grease after almost every use (and stop pumping as soon as I feel any backpressure.)

If it's a brand new unit there is some grease in between the trash cap held in by the snap ring and the main rear seal....just part of the assembly process and will stop after one or two uses, if it's one of the first 30 2011 models it's a bushing lower unit and will need to be replaced with a newer dual ball bearing lower unit. If neither of those needs new seals.