1973 65hp PowerShift II-stopped abruptly-lower unit?

[juggernaut22us]

I received this boat/motor on a trade. Before I took out first time I changed the lower unit gear oil and updated sparkplugs. Motor ran great about the 20 times I've had it out. I know the lower unit seals need replaced and water was getting in. I took it out the last time, launched boat, got on a plane, was circling back to get wife and daughter from dock and I heard a clank and lost pushing power. the engine still ran but if I gave anymore than an idle speed it would stall.... I had to restart several times to get back to dock as I had no pushing power as if the lower unit gears went bad or something. I guess I need some driection as to where I should start troubleshoothing the issue. I know the top end is fine and it must be something in the lower unit or prop.....Any ideas on what happened to my engine, why the sudden clank noise and stop. Is a lower unit easy to replace or rebuildable?

 

[juggernaut22us]

Re: 1973 65hp PowerShift II-stopped abruptly-lower unit?

I received this boat/motor on a trade. Before I took out first time I changed the lower unit gear oil and updated sparkplugs. Motor ran great about the 20 times I've had it out. I know the lower unit seals need replaced and water was getting in. I took it out the last time, launched boat, got on a plane, was circling back to get wife and daughter from dock and I heard a clank and lost pushing power. the engine still ran but if I gave anymore than an idle speed it would stall.... I had to restart several times to get back to dock as I had no pushing power as if the lower unit gears went bad or something. I guess I need some driection as to where I should start troubleshoothing the issue. I know the top end is fine and it must be something in the lower unit or prop.....Any ideas on what happened to my engine, why the sudden clank noise and stop. Is a lower unit easy to replace or rebuildable?

1) What would cause the motor to go from planing speed wide open throttle to a "cranking sound" then no thrust power only trolling speed power?

I know that the seals on the lower unit needed replaced an water was probably getting in... any ideas?

 

[halfmoa]

Re: 1973 65hp PowerShift II-stopped abruptly-lower unit?

Would you say it feels like you're "slipping" i.e. if it had tires instead of a prop you'd be spinning the tires? A spun prop hub is always a good place to start looking ESPECIALLY when the boat will putt along but not accelerate. Make a mark on the hub and a mark on the prop and take it out on the water. If the marks aren't aligned after you've hit full throttle then you've spun the hub.

 

[juggernaut22us]

Re: 1973 65hp PowerShift II-stopped abruptly-lower unit?

Would you say it feels like you're "slipping" i.e. if it had tires instead of a prop you'd be spinning the tires? A spun prop hub is always a good place to start looking ESPECIALLY when the boat will putt along but not accelerate. Make a mark on the hub and a mark on the prop and take it out on the water. If the marks aren't aligned after you've hit full throttle then you've spun the hub.

*new boater here* First boat this year was a 12ft v-hull with a 6hp johnson, took it out like 20 times and decided to upgarade to the 16ftMFG 65hp johnson. Anyways just thought i throw that out since I didn't know what the "hub" was and had to do a search. That makes since what your saying maybe the prorpeller isn't sticking to the HUB in which case a new propeller would correct it. I'll check 1st chance I get to see if that sucker is slipping or not... Thanks

 

[juggernaut22us]

Re: 1973 65hp PowerShift II-stopped abruptly-lower unit?

In the event I decide to buy a new propeller, what would be the best one to get for a 1973 MFG Super Caprice?
13-3/4 X 17
12-3/4 X 21
14 X 21
13-1/8 X 16
13 X 18
13-1/2 X 22
13-1/2 X 24

 

[juggernaut22us]

Re: 1973 65hp PowerShift II-stopped abruptly-lower unit?

the 1973 MFG Super Caprice is 16ft fiberglass runabout boat.... with the 1973 65hp Johnson Powershift II....I'm looking for the best prop size and pitch any suggestions?
In the event I decide to buy a new propeller, what would be the best one to get for a 1973 MFG Super Caprice?
13-3/4 X 17
12-3/4 X 21
14 X 21
13-1/8 X 16
13 X 18
13-1/2 X 22
13-1/2 X 24