I just bought a used 2002 Genesis with 49 hours on it. Looks in good shape. Engine compartment very clean. Looks like it's been looked after. First time in the water it started fine but seemed to lack take off power. Max speed was 35mph. Engine sounded sweet not misfiring but no chance of getting to 55-60mph like I was told. What are the first things to check before I have to take it to a shop?