[imported_fish_on]

I have a 77' Mercury 150 Black Max serial number 4967664 on an 18’ Skeeter bass boat. I use a 40:1 fuel mixture and have recently replaced the spark plugs and fuel pump. My problem is this: I give full throttle, my RPM's increase, yet I can't seem to get out of the water for about 1 to 2 minutes! Finally the boat starts moving, then really gets going, and before I know it, I am doing 55 MPH plus! Is there a reason (other than having an older engine) why I am not getting out of the hole faster?? Any and all comments are greatly appreciated.

[orca]

G'Day. Reckon that you are using the wrong size prop. What are your maximum revs? you should get about 5500RPM flat out. try another prop about 2" pitch smaller. Also the motor may be set at the wrong height. The cav plate should be approx leval with the bottom of the boat.

[Nacman]

Hey Fish_on...I had a similar problem on my 92 merc 150 not getting out of the hole too quickly but going exactly 53 mph once it did. I found that one plug wire was not on correctly and once I fixed that situation and got all 6 cylinders firing, I got on plane in less than 10 seconds with me alone in my 18 foot bass boat. I also now attain 65-67 mpg by myself as well.Just a thought-nac

[Dhadley]

If the motor is running on all cylinders, you may be able to play with the set up and raise the X dimension. If the motor is running correctly, this is a classic example of the motor being too low. As suggested, verify the running condition and get back to us. I'm guessing you have a jack plate so raising the motor will be easy.Good luck!