50hp 15 bassboat will not plane out

[destol cooper]

Some how I got to be the one in the family to work on boats. Currently working on my brothers 15 Glastron bassboat with a 1979 mercury 50HP model 500 motor. The problem is it will not plane out. Seems to run fine, but will not get on top of water.Cleaned carbs,rebuilt fuel pump,no water in hull,new plugs,changed fuel connections.Prop is in pretty bad shape,can anyone tell me the correct size and pitch for this setup.Also any other help with this planing problem would be appreciated<br /> Thanks destol cooper

 

[Jesster]

Re: 50hp 15 bassboat will not plane out

Michigan Wheel suggests a 11 1/2 x 13 for a boat that size and with that same model motor. Do you know the current dia. and pitch of the prop? It would help as prop size and pitch can put you over/under propor RPM's for your motor. So just going by mfg. suggestions isn't always a good idea.

 

[LubeDude]

Re: 50hp 15 bassboat will not plane out

Providing you are not dropping a cylinder, Which is a deffinate posibility, A baddly dinged up prop will cause this also. Make sure the trim pin is in the lowest available hole.

 

[Chinewalker]

Re: 50hp 15 bassboat will not plane out

What's the compression in all four cylinders? Like to see it above 100psi and within 5% of each other... Sounds like you might be dropping a cylinder. <br /><br />If the motor is revving up but the boat's not moving, look into the prop - might have a spun hub...<br />- Scott

 

[destol cooper]

Re: 50hp 15 bassboat will not plane out

Thanks for all responce's,as soon as I get the starter fixed I'm going to get a spark gap tester to make sure I have good fire to all cyl's this will tell me that all cyl's are fireing and not dropping out (correct)The compression is 110 to 115psi.<br />Thanks again fellows<br /> Destol cooper

 

[CU2NITE]

Re: 50hp 15 bassboat will not plane out

A stabilizer fin will give you great proformance getting out of the hole. I used to have the same boat and this fin (whale tail) was the best investment I made to enhance the proformance.(30-40 BUCKS) Good luck and let us know.<br />CU<br /><br />--------------------<br />RUNNING THE MOTOR WHILE LISTENING TO THE HORN WILL MAKE YOU MORN!!