50HP 507X8D Not running properly no more than 6mph

fsantana14

Cadet
Joined
Mar 7, 2011
Messages
6
Hello Guys,

I have this problem were my motor sounds and revs properly but on water it just has no power to move the boat, how can check for a spun hub or electrical problem, last comment that I receive here was to check and change all electrical wire but no sucess. Also I receive a comment about the power pack or CDI unit.

Any recommendation?

Thanks in advance
 

pnwboat

Rear Admiral
Joined
Oct 8, 2007
Messages
4,251
Re: 50HP 507X8D Not running properly no more than 6mph

On the back of the prop, take a sharpie magic marker and draw a line across the hub and outer portion of the metal prop itself. The line on the hub and prop itself will be aligned. Test it in the water. If the lines no longer match up, you have a spun hub.
 

jerryjerry05

Supreme Mariner
Joined
May 7, 2008
Messages
18,183
Re: 50HP 507X8D Not running properly no more than 6mph

Does it rev up in the water while under load?
Just to eliminate any other problems.Do a compression/spark test.Then do the prop check like pnwboat suggested.
 

fsantana14

Cadet
Joined
Mar 7, 2011
Messages
6
Re: 50HP 507X8D Not running properly no more than 6mph

Hello jerryjerry05,

it does rev on the water with load, but not enough power to move the boat. I check compression and get 110 on both. What I notce is the on the rectifier on the connections is broken, can this affect?
 

jerryjerry05

Supreme Mariner
Joined
May 7, 2008
Messages
18,183
Re: 50HP 507X8D Not running properly no more than 6mph

Probably not.Do the prop check.J
 

rglasgow

Recruit
Joined
Oct 15, 2011
Messages
3
Re: 50HP 507X8D Not running properly no more than 6mph

the loose electrical connection definitely can have an effect, but the thing that comes to me is that the flywheel can have low magnetism which decreases the ability of the stator to produce the 300volts ( 180volts if replaced with a new CDI stator). I have this model engine.. If you find a source of magnets (rubberized strip) 1 and one eight width by 3 sixteenth thickness, please let me know. It is a common problem but have not heard how to solve it. There are not any new flywheels available.. Mercury Quicksilver sold the last on in the country last week which sat on the shelf for 20 plus years.
 
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