I guess it would be the conditions
I sail in Raritan bay NJ. Most of the time the wind just dies. So I find my self motoring a little more than I'd like to. I think the 1gm runs great! It's an awesome little engine! I just think I'm running it a little too hard and it's pretty loud! I thought the 2gm would be a bit smoother and quieter. I also feel I'm getting a pretty good deal on this 2gm! But if it's sounds like it's not a good idea to change, I'll stick with the 1gm. I love that little engine!