40hp Mercury prop pitch

[Blake0912]

I have a 1992 Merc 40hp on the back of the 13ft Whaler. It came from the factory with a 12p prop back in 1992 and has never been changed. My question is, It has a problem getting on plane with more than 2 people and gear on the boat you have to almost stand up and push down on the bow to get it to plain out, we have always just delt with it. So would getting a different pitched prop help me out for planing? I don't know much about props any advice would help thank you.

Note: I do not have a tach on the boat so i'm not sure what the max RPM is.

 

[Silvertip]

Re: 40hp Mercury prop pitch

Without a tach there is no way for you or anyone on this forum to know what's going on with the engine. However, do you perhaps have the engine trimmed up too high during hole shot? That would shoot the bow way high. Trim the engine in and see what happens. 12P however does sound about right for that boat. Are you also certain the engine is running on all cylinders and making full power. Is the throttle plates opening fully in the carbs. has the engine been properly tuned??

 

[Blake0912]

Re: 40hp Mercury prop pitch

I always plain out with the motor all the way down, if it is trimmed up the least bit the bow will bounce up and down like a low rider. We are the original owner of the boat and the motor runs the exact same as it did back in 92, But yes it was tuned up within the year. I have never had a huge problem using the 12p prop was just wondering is using a different/larger prop would help it plain out better with a load, or for say pulling a tube etc.

 

[steelespike]

Re: 40hp Mercury prop pitch

My very limited experience the smaller Whalers struggle a little with a load.
Yes a prop change should be able to help,but you shouldn't make any prop change
without a tach to help tell what prop and to tell if the new prop is right.
We need your max rpm and speed to tell how your setup is working.