I cant get it up.........on plane

[jfrost1920]

I have an 83 merc 50hp and It take along time to get the boat up on plane so I can trim it out. It easily takes 200yrds or something to get it up enough to start trimmiing the motor. It will get up to 25 or so in the end but out of the hole is slow slow slow slow slow. I have a 16ft fiberglass 1985 mon ark and a 14p prop on it. 2 batteries and a 12 gallon tank. It doesnt take on much water. Clean fuel filter, new fuel lines to the motor, primer bulb, and spark plugs. What could be makeing it so slow out of the hole? Is there something else I should check into or is this just the life with an 83 50hp. Any advice? Thanks alot guys. This forum is great.

 

[Barnacle_Bill]

Re: I cant get it up.........on plane

For starters, is it firing on all cylinders? Is the boat loaded evenly? Do you have T&T? Do you know the RPMs at WOT? If yes to the first 2 questions, try tilting the motor in 1 notch.

 

[jfrost1920]

Re: I cant get it up.........on plane

Compression is good on all 4 cyl. boat is loaded evenly. It is on the second hole on my tilt. I usually start with the motor trimmed all the way down and then go. When I start with it trimmed up too much, then the nose of the boat goes up in the air and I cant get on plane. So i start with it trimmed down all the way and then about 200yrd later I can start trimming the motor up. I dont have a tach so I dont know what the RPMs are.

 

[crazyclam]

Re: I cant get it up.........on plane

IS this a recent problem.....have you changed the prop lately???? a prop change makes all the world...you can tell us if your girl weighs 400lbs dont blame it on the engine

 

[jfrost1920]

Re: I cant get it up.........on plane

No its not a recent change really. It has a 14p prop on it. And my wife is skinny and hot and I never take her with me anyway. Its usually me and my brother so about 365lbs in people together. My dads boat will do 35 easily with 3 guys and he has a 50hp fiberglass boat but its and 01. Would dropping down to a 13p maybe help? I was basically just wanting to know if there was something major that could be holding the HP down.

 

[BR]

Re: I cant get it up.........on plane

Hey j-
From what you describe, I'd say this is not normal. I've got a '73 50hp on a 16' trihull with a 13" pitch prop and it will definitely not take 200 yards to plane out. Here's my .02:
1.) Check to be sure you're not carrying extra weight in the way of water in the bilge. Do you trailer your boat after each use or does it stay docked? You may want to pull it out of the water and check the drain to make sure you're not carrying a couple hundred extra pounds.
2.) When you try a hole shot does the motor sounds as though it's revving without going anywhere or does it sound as thought the motor is straining under load? If it's revving you may have a prop with a spun hub. If it sounds as though you're straining under load and its just taking a long time to wind up, you may have engine trouble. But it could be something as simple as fuel starvation. Check your fuel line connections, primer bulb and vent. Next time out, try pumping the primer bulb and see if she picks up.

Good Luck.

 

[jfrost1920]

Re: I cant get it up.........on plane

Thanks for the good advice. I do trailor it every time I go and make sure its dried out. It does take on water but only about 5 gallons maybe in a day and I CANNOT find the leak anywhere!!! And I dont know what a hole shot is but if I go from a standstill to max throttle, it takes right off but only to about 10 or so mph then it takes another 200 or 300 yds at least to get to 25mph and plane out. I know a guy that has a 13p prop that I might try to borrow and see if the hub is spun and if a 13 will help any. Im going tomorrow and Ill try the primer bulb as we are motoring to see if that helps or not.