Shear pin question - old Sears/Eska motor

EKavanagh

EKavanagh

Active member
I was just given a 1970 Sears outboard. It runs well and I had a professional outboard guy check it out and give it a clean bill of health. I know the thing uses shear pins, but can't figure out where they go (I've never had such an outboard). I took the cotter pin off the nut on the back of the prop and removed the nut. The damn prop still wont come off. Either a pin is holding it on and I just can't find it, or the prop is somehow fused to the shaft.

Does anyone have experience with this kind of motor? Motor is a 7HP, made for Sears by Eska. I can upload pictures tomorrow.


Ed
 
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It runs well and I had a professional outboard guy check it out and give it a lean bill of health.
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Two things come to mind;

(A) The shear pin is partially or fully sheared and the pieces are hanging up and hindering the removal of said prop.

(B) If the mechanic checked out the entire outboard, including the lower unit, how come he did not discover this during his inspection? Did he not check for a damaged prop seal, bent prop shaft, broken shear pin, etc.,,,, when he gave it a "clean bill of health"?

 
Dave, he didn't take the prop off. The motor hadn't run in 20 years and he cleaned it up and got it running.

Do you know if the pin should be accessible without taking the prop off? I've never had a motor that used shear pins. I'm just trying to find where they go.

Thanks
 
Boy does this sound familiar....

chances are that some one used a nail as a shear pin and it has smeared and bent rather than shearing. Once bent the nail will be pinched between the prop hub and the prop shaft making it really hard to pull off.

It is probably similar to my 3hp johnny rude from 1953.

There is a pin about an inch long that goes through a hole in the shaft. the prop has a groove in the back of its hub that slips over the pin and the prop nut keeps the prop from backing off the pin. Depending on the design there might be a thrust washer in there somewhere and the prop hub may not be built into the prop.

http://www.tanaka-usa.com/index.php?section=129

The eska is a tanaka so look on the link above for a manual or parts diagram.
 
Ed, At Antique Outboard Motor Club get togethers we used to take a sanitized (drained) Eska with a rope attached and have a "Eska Toss " off the dock. Whoever threw it the furthest had to take it home;-). All the shear pin advice is good, the prop needs to come off to get at the shear pin. My guess the prop is just rusted on and will take some force and or heat ot get it to budge. Make sure you get it to come off before you use it or it will let you down at the worst possible moment. Also when you start using it carry some spare pins. Good Luck.
 
Tom, thanks. Maybe at $0 it was priced too high!

I was going to use it on a local river, heading upstream and being sure to bring along some oars.

Ed
 
My guess the prop is just rusted on and will take some force and or heat ot get it to budge. Make sure you get it to come off before you use it or it will let you down at the worst possible moment. Also when you start using it carry some spare pins. Good Luck.
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Ed

Be aware that you stand a good chance of damaging the prop during the removal procedure if indeed it it "frozen" to the shaft. Your other option is to leave it alone,,, for the time being,,,, and deal with it when it does fail. As Tom said, it will fail at some point and it most likely will not be convienent at the time. Kind of similar to driving a car around on old tires with no spare along.

Now you get to decide your best option. :>) :>)
 
the nut and cotter pin were BEHIND the prop, correct? If I'm remembering an old Evinrude I had, the shear pin went THRU the prop/shaft, just ahead of the nut, and after assembly there was a rubber cone that fit over the whole assembly. Should be easily visible and tap it out with a punch. Support the motor so the shaft is verticle and use some liquid wrench for a few days to soak thru.
 
Jim,

Yes, the nut and cotter pin are behind the prop. I looked all over and did not see a pin. I will look again, and ask others to look, before I start swinging a hammer.


Ed
 
Hammers and prop shafts don't normally go together. There should be a way to use a wheel puller, such that you'd use to pull a flywheel or v-belt sheave. Should be able to borrow one from the local auto parts store. But if it's on that tight you might bend the prop blades so be careful....soak it as I suggested. There's not a pair of holes on the prop less than 1/2" from the back of the prop probably less than 1/4" in size? If not that would suggest a splined shaft.
 
Thanks everyone. Tom had it right, the shear pin is covered by the prop and the prop is rusted or somehow fused to the shaft. A nail was probably used at some point, according to the prior owner. I'm soaking it now and debating on how much energy and money to put into this project. I see a used evinrude on Craigs List that might end up being cheaper to own than this free Eska.

Ed
 
The old outboards with pins were a pain in the behind. However, when I was lobster fishing we were always getting wound up, hitting a skid or a rock with the blade, hitting a wood buoy, on and on. The result was a broken shear pin which required leaning over the stern to replace ..best with someone holding on to your oil jacket. But it was fixable, cheep and usually you could break a lot of pins before the blades got too chewed up inside to use. AND, even if I was out of pins we always had nails aboard for fixing the old style wood lobster traps, an added bonus.

With the new motors, hit a rock, and its very easy to be out $3000 for parts plus labour. Grrrrr.....
 
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