Johnson 1967 60HP Vibrating lower power

[RickyAust]

Guys,

six weeks ago I ran into some rocks and damaged my prop and also snapped the shear pin. I have replaced the two of these items and today I took the boat out again for the first time since the repairs. Motor started perfect and idled well. I put the motor into forward and all seemed fine and low speeds, however when I tried to accelerate and put the motor under more load, the motor seemed to be vibrating and I could not get hardly any power at all. I can usually get the motor to appx 36mph, however today I was lucky to reach 5mph and was worried I was going to get stuck out in the water again. I re-checked the shear pin, and all ok. Could there be gear case damage?

 

[tashasdaddy]

Re: Johnson 1967 60HP Vibrating lower power

yes, but check other reason, before tearing into it. compression, spark. your going to need a manual. just for kick here's some tests for the electrical system incase you are dropping a cylinder firing.

http://www.boatpartstore.com/page28.asp

 

[F_R]

Re: Johnson 1967 60HP Vibrating lower power

When it won't go, is it making grinding noises? Is it revving up but like slipping?

 

[RickyAust]

Re: Johnson 1967 60HP Vibrating lower power

Yes it does seem like that. It runs along fine at low speed, but as soon as I try to speed up it does that. What could it be?

 

[RickyAust]

Re: Johnson 1967 60HP Vibrating lower power

I have all the service manuals for this motor, however I am not what you call mechanically minded. Is there any easy way of telling if I have damaged the drive shaft or prop shaft?

 

[F_R]

Re: Johnson 1967 60HP Vibrating lower power

Grinding noises indicates internal damage in the gearcase. Vibration goes along with this. In addition, you could have bent the gearcase. Only a thorough disassebly and inspection will reveal how much damage is done.

However, slipping (like spinning your wheels on ice) without grinding indicates a spun hub in the propeller.

 

[RickyAust]

Re: Johnson 1967 60HP Vibrating lower power

I replaced the prop after the collison with the rocks, and also the shear pin which had snapped. I read about the Prop hub last night, but dont know where its located to check for this?

 

[bluejim115]

Re: Johnson 1967 60HP Vibrating lower power

The hub is located inside the propeller.

 

[RickyAust]

Re: Johnson 1967 60HP Vibrating lower power

In know that..I would assume there is further damage further up in the gear box. I have a local mechanic who can look at this for me. At what point do you say, it cant be repaired and its better to replace the whole lower unit? Also, are there any companies who sell these for this motor?

 

[RickyAust]

Re: Johnson 1967 60HP Vibrating lower power

I checked my motor against my friends motor. with the motor in neutral when you spin his prop by hand, it turns at least 3 spins. when you spin my prop, it is lucky to spin 1/4 of a full spin. Any ideas?

 

[F_R]

Re: Johnson 1967 60HP Vibrating lower power

I checked my motor against my friends motor. with the motor in neutral when you spin his prop by hand, it turns at least 3 spins. when you spin my prop, it is lucky to spin 1/4 of a full spin. Any ideas?

Doesn't sound like it's going into neutral. The prop will turn back and forth a bit in gear. Maybe your shift linkage has come undone. Might not even have anything to do with hitting the rocks.

Take off the inspection plate on the side of the motor about half way down. You will find another plate behind that one. Take it off too. Inside you will see the shift rod and connector. It should move up and down when shifting, and not be disconnected. If it is going up and down, but not shifting the lower unit, something is busted somewhere.