1972 johnson 50 hp prop not spinning motor running

Ok i have 3 questions actually. I have a 50 hp johnson model number 50esl72c. Just 1 month after i got it (used obviously) i broke a prop and had to drive around with only 2 blades (which i later found out was terrible for the engine). When i replaced the prop with a new one (slightly smaller about 1 cm) the first time i took it out, it seemed like the prop wasn't catching enough water, because every few seconds while going forward i would stop unless i varied the speed constantly. Later when i got it on land i noticed that the prop itself would stop spinning after being in gear for a few seconds. Note* the engine seemed to be running fine but prop would only spin for a few seconds once in gear. A few days later i tested it again and the prop would not spin at all. Engine would run and when you put it in gear the rpms would just shoot up. I was thinking the problem is in the lower unit so i ripped it open and now i'm confused. Once apart the prop would spin just fine when you spun the drive shaft by hand. But when i put it back together it still wouldn't spin at all when put in gear. So my questions are. Does the lower units seleniods control whether or not the gears engage? because a friend of mine thought that they might be bad. Next is there anyone i can contact to tell what lower units fit my motor if it is a lower unit problem? because i found a few on e-bay that look similar but from different years and with different hp levels and i want to know if they will fit. And lastly does that sound like a seleniod/ lower unit problem or what? Keep in mind though with the cowel off you can see some motion on the engine like something is engaging when you shift (engine off) from neutral to reverse or to forward. I just really need to know if buying a new lower unit will solve the problem or not.

Re: 1972 johnson 50 hp prop not spinning motor running

ok...<br /><br />The ESL units defaulted to forward when there is no power applied to the soleniods..<br /><br />in other words, if the two wires running up the leg into the cowling are disconencted, then the unit should be in forward gear..<br /><br />The solenoids in this unit controls an oil pump..<br /><br />If I were you, my first step would be to check that you have oil in the lower unit to pump.. won't go anywhere without it..<br /><br />second thing.. does the new prop have a spun hub??<br /><br />take the prob off the LU, and turn it over, inside the prob will be a ring of rubber, get a felt tip pen and mark the inner and outer rings around the rubber so you can see later if they still line up.<br /><br />rgds<br /><br />Franki

Re: 1972 johnson 50 hp prop not spinning motor running

thanx thats a start. well first off i know that it had oil in it, cause after we ripped it apart i filled it back up. But that does mean its not the solenoids cause it's not in gear at all, its definitely not in forward because even with no prop on the bottom, the shaft doesn't spin when you run the motor in gear. So i'm figuring it must be the connection at the top of the drive shaft (under the cowel) sound right? if so now what to do/check

Re: 1972 johnson 50 hp prop not spinning motor running

tony . did you drop the lower unite and look at the end af the shalft . had one to break at the spline . where it went in the bottom of the enguin<br />i have one of those hanging in my shop . it is compleat .just changed to a manual shift .be sure to use eletrishift oil the regular or manual shift oil is to thick papasage

Re: 1972 johnson 50 hp prop not spinning motor running

yep tried that already. when i took the lower unit apart i tried spining the prop (well the shaft the prop spins on). When it was apart and i turned the drive shaft by hand (the long one that goes up to the engine), the shaft tha turns the prop would spin just find. No grinding or slipping. But when i put it back together nothing. I'm starting to think its whatever spins in the gearcase isn't sinking up with the drive shaft and i'm stuck in neutral, anyway to check if thats it. i'm trying at all cost to avoid having to take it to a mechanic.

Re: 1972 johnson 50 hp prop not spinning motor running

Pull the L/U back off and inspect the spline at the top of the drive shaft. See if they are either stripped or have metal shavings in them. Also, what kind of lube did you refill the L/U with?

Re: 1972 johnson 50 hp prop not spinning motor running

i think you have a spunout prop do what frankie said about marking the prop. the rubber can be replaced sent mine to ellis propeller in jacksonville fla . it onley slipped when almost plainoff.freight and repair was less than 40.00 bucks . mine is s.s.

Re: 1972 johnson 50 hp prop not spinning motor running

Naw when i pulled the lower unit off i look at the top of the drive shaft and it was find, no stripping at all. And i don't think its the prop because the shaft that the prop is on doesn't spin at all when the engine is on and put into gear. So even if the prop was spun, the drive shaft would still spin and it doesn't.

Re: 1972 johnson 50 hp prop not spinning motor running

tony i have a foot that will work it is off a 73 replaced it with a74 standard shift will sell cheap.e mail me [papasage10@yahoo.com]

Re: 1972 johnson 50 hp prop not spinning motor running

Did this thing ever work with that LU???<br /><br />It sounds like a wrong length shaft or wrong diameter..<br /><br />If I understand what you have written correctly, when you had it off the motor and spun the shaft, the prop shaft spun correctly, but when installed moter rotation is not translated correctly if at all.. if the spline is not clagged, and its seating correctly, then your gearcase is probably clagged. take it apart and have a look.. its a pain, but not that hard.<br /><br />Are you trying to adapt a different Foot on that OB???<br /><br />regards<br /><br />Franki

Re: 1972 johnson 50 hp prop not spinning motor running

No the lower unit worked fine for quite awhile, its the original one the motor came with. The problem started just after i broke my first prop. Thats why i think i shook something loose by running it with 2 blades. I've heard that it is possible.

Re: 1972 johnson 50 hp prop not spinning motor running

looking at the breakdown the pinion gear could be striped or broken off it fits on the lower end of the shalft.

Re: 1972 johnson 50 hp prop not spinning motor running

Did you refill the lower unit with the special oil required for the electrically controlled unit?<br /><br />Does it use a shear pin?<br /><br />Have you checked the propeller for a bad rubber insert? (hub)<br /><br />Have you done the electrical diagnostics to acertaiain the correct voltage at the correct wire(s)?<br /><br />Did those units have the (extra) little screw on the lower unit that was a pivot pin? They had a tendancy to screw everything up if removed by accident.

Re: 1972 johnson 50 hp prop not spinning motor running

i'm thinking it could be the pinion gear in the lower unit. Except when the lower unit was apart and i manually turned the shaft, the prop spun. (and yeap i've check the prop its not the rubber, the shaft doesn't spin even when the props not on when the units running) so i'm fully stumped. I'm gonna have someone come check it out, if its the lower unit then i'll just buy a new lower unit.