lower unit problem on a 57 jhonson

[mikehowe]

ok i took my boat out it was running great tell i went full throttle then it felt like the gears where slipping it would slow down then get a bust of speed but the motor it's self is running great just surges when at full speed any answers on the problem

 

[tashasdaddy]

Re: lower unit problem on a 57 jhonson

possible drive pin, or spun prop, there is an inner metal hub,outer metal hub with the fins, sandwiched between is a rubber gromet. if this goes bad the prop slips. drian you lower unit and see if the are metal shavings in the oil.

 

[HighTrim]

Re: lower unit problem on a 57 jhonson

Sounds like your props hub may be spun.

Draw a line across the hub and prop, or use the cotter pin as a center line. Run the motor until you hear it 'surge', then pull it out. If the lines are no longer lined up, the hub is spun and will either need to be rebuilt, or you will need a new prop if your current one is in poor condition anyways.

I recommend the new 2 piece props that are out now, so the if the hub spins again, or you damage the blades of the prop, you can simply buy the specific item rather than the entire assembly.