So this outboard that I use sometimes is a 115hp mercury 4 stroke EFI salt water series. I don't know the year. This outboard has the absolute worst throttle in existence. What happens is after it is in gear and I try to increase RPM slowly, I end up pushing the lever quite a ways because it does nothing, but whenever it feels like it, which is very variable, the RPMs will suddenly shoot up to between 1/2 to 3/4 throttle. Although occasionally it will cooperate and I can get the RPMs to a little bit above idle where I want it. Although whenever it shoots up, I can almost always bring it down to where I want it to be. And occasionally the RPMs will just change by themselves at any random point (up or down). All this is the same in forward and reverse. I'm not sure if this would be the fault of the control box or something in the engine. I should probably also mention that the gears in the transmission (not lower unit gears) are quite badly shredded, as it grinds like hell when going into gear, although it doesn't grind once in gear.
