2 props on the bottom of the lake

[SKIBUM1M]

I have a 1966 60 horse johnson and am having major problems with my props. this is a pin drive prop and the first had the cap and cotter pin. I was coming into the dock to fast so used reverse and it didnt seem to work. i loaded the boat and noticed i had no prop. looked for it but no luck so i bought a used one I didnt have the pin and cap so i used a shear bolt. Everthing seemed fine with it but when i had the engine run well for a day the rubber broke free. Wanting to get out on the water while i wait for a new one to get here from ebay i drilled a hole thru the prop and hub. I installed a bilt directtly thru the prop body, hub, and the shaft. Today the engine seemed to run the best it ever has but when i tried to really take off nothing happend. a second prop at the bottom of lake champlain. I have one comming next week that is new old stock and i dont want to lose a third. Any ideas on why i cant keep a prop and how to keep the new one. My idea is to install a second bolt thru the shaft hole for the cotter pin so if i do lose the shear bolt at least this second bolt may keep it on the shaft.

 

[kenmyfam]

Re: 2 props on the bottom of the lake

Post some photos of what you have done so far.

 

[SKIBUM1M]

Re: 2 props on the bottom of the lake

Well i would but the props are at the bottom of the lake. I just have a shaft in the middle of where the prop should be

 

[jonesg]

Re: 2 props on the bottom of the lake

try a nyloc nut on the prop shaft, if its backfiring off or preignition throwing the props off it will still do it but the nut will not come all the way off, it will just loosen. I'd keep an eye on it and take it easy, no high speed reverse braking.

A thru bolt will shear off if theres any play between the bolt and the hole at all. It becomes a problem when the hole starts to oval, see if yours is oval now.

If it still does I'd say screw it and weld a washer on the end.

 

[Lion hunter]

Re: 2 props on the bottom of the lake

I can't even fathom that happening. Are you bending the cotter key over on the prop nut? Is the shear pin breking when this happens? For the nut to unscrew an break the cotter would require that the shaft and nut spin independently. The only way I could see that occuring if the prop nut was so loose to allow the prop to back off the shear pin against the nut and turn it, or it is so tight that when the shear pin breaks the friction causes the nut to come off.

 

[SKIBUM1M]

Re: 2 props on the bottom of the lake

this is pin drive. it does not have a prop nut. it does not have thru prop exhaust. at the back of the prop the hub extends about an inch which has a hole thru it and a 5/16 pin thru the hub and shaft. the last time i lost the prop i had a bolt with a nylock nut thru the hole and had nothing left on the shaft. no prop or bolt. so aparently it sheared the bolt without hitting anything. aparently this engine when it is running right is putting out enough torque to shear the bolt does this sound possible?

 

[tashasdaddy]

Re: 2 props on the bottom of the lake

the plastic cone is called a prop nut. are you using stainless cotter pins, if not that is your problem. is the thrust washer in place between the gear case and prop?

 

[ezeke]

Re: 2 props on the bottom of the lake

It is important that the propeller not be able to turn on the shaft when mounted; this requires that the correct thrust washer be in place before the drive pin and that the stainless steel OEM drive pin is the correct one.

There are two different drives for the 60HP motors, with different thrust washers and drive pins.

Also, you should use the largest diameter stainless cotter pin that the propeller shaft will accomodate.

 

[SKIBUM1M]

Re: 2 props on the bottom of the lake

i got a 3rd prop today with a prop nut and a new pin and ss cotter pin. took it out on the lake and it ran good and best of all i had a prop when i pulled it out. top speed was only 17 mph according to my gps. the battery only had 8 volts which may have been causing the spark to break down. I will try again witha charged battery when the rain stops. I cant believe this engine has no charging system.