Bottom line you have to first remove the outer motor gear to see if the key (as drkangel says) is still totally intact. Lets face it the key is only about 5/16" long and can roll very easily. But I thought you said this was a new motor.....and your still having the same problem? Something that I noticed on some of my motors is the gear is not as thick as the area where it sits on the shaft. So even when the nut is fully tightened the gear could still be moved on the shaft. I have 5 Currie motors and 2 of them came with a thin washer on the motor shaft behind the sprocket (gear). I am sure the manufacture relished there was a problem and added this washer to act as a shim so the gear would be held tightly in please. Otherwise, the gear would be allowed to "rock" on the shaft causing damage to the key. Bob

Luckily I just happen to have an extra key laying around. Time to pull out the trusty robot pliers. Too much torque u say?

Any instruction on how to reinstall gear after putting the key in place? Once I get it to the thicker part where the gear should sit, the thicker part of the rod pushes the key out or the gear gets stuck at the very end of the thicker part. If I keep going like I am I'm gonna end up breaking the spare key.
Sheared key and replacement side by side

Yep. I just got this motor a few weeks ago

When I put the key into place I can push the gear all the way down onto where it should sit on the thicker part of the rod. The key however is pushed out and just sits on the thicker part doing nothing for the gear itself. If I hammer this down I will only be beating it into the shaft, not the gear. Any help guys?

Remove sprocket.
Remove other half of key from groove in shaft.
Set key into shaft, key turned 90 degrees from in picture, flat face into shaft.
Slide sprocket on.
Tighten nut.

Reduce low rpm throttle! ... or stock up on 4mm key stock!

Hmmm. So I appear to be missing something. I don't have a slot on my motor shaft, I do have both pieces of the sheared key though.

You have a grove...slot (key way) in the shaft. The key is still in it and was sheared smooth so it looks like there's no key way (slot). You need to look for it and use a small screwdriver to pick it out.

What country do you live it? I ask because those keys are available at most local hardware stores for 50 cents or less. You may not find the exact length but you can cut it to size needed.

Look around the circumference of the shaft ... there should be a hole ... exactly the shape of the key.
If you have both halves of the sheared key, one half fell out of this hole-slot.

Put the new key in this hole.
Slide sprocket on.
Add nut and tighten.

Looking at both the newest motor and the original, this is the only variation in the circumference.

So i am guessing that this slot is where i need to be prying?

Yup!
Other half of key is in there.



If you can't dig it out, you might use 1/8" bit into softer key.
Drilling, vibration might loosen it, or give you a better pry point.
1/8" hole + lightly tighten sheet metal screw in hole = good handle to pull out key?

I know this is supposed to be simple but this key is pretty much bonded into place. My drill bits are silver wood bits that are no good for this job. They are only making dimples. My screwdriver as a pry point is useless.
Remember I am the resident stoopid man here and for all the other first timers here can either of the knowledgeable DA's (or anyone else) here show me the exact bit I need to buy.
If I remember correctly from my glazing days I need a gold 1/8" metal bit or at least some metal self tapping screws. The problem is that I had fell into the convenience of paying someone to do this stuff for me over the years and have forgotten a lot of good stuff.
I live in Florida

Any 1/8" "steel" of high speed steel drill bit.
1/8" dbl ended auto body drill bit is probably cheapest, of reasonable quality. (used for 1/8" pop rivets.)
Available at most hardware or autoparts store.

You do relize the key starts close to or at the end of the threaded porsion of the shaft? I would consider using a small punch, chisel, screwdriver or ever a pair of wire cutter plyers to pry up the edge of the key at that point. BTW, looking at the condition of the shaft I am wondering about the condition of the sprocket. Even if you are using a new sprocket the shaft is basically shot and you will likely have continuing problems with it shearing keys. The sprocket needs to fit snugly on the shaft so it doesn't wobblle or even move foreward and back. Who knows you may get lucky and save everything but you need to learn how to ease your starts with the throttle and maybe go back to 24v. Unless of course you don't mind doing these constant repairs and buying motors. I myself would rather just ride my bikes and invest my money in good batteries. Bob

I absolutely would rather spend my money elsewhere but, I am still getting a feel for the bike.
Thanks to both of you guys, I wanted the bike running again today and I got the bike running again yesterday.
I admit that I may be more adventurous than most, but really this bike is a personal training ground for skills I neglected to learn earlier and skills I have long forgotten. All things can be applied to projects around the house as well as to the upkeep of our cars. I thank you all for being patient with me. My posts are meant to make me able to fix things as well as provide information in layman's terms for noobs like myself.
Im a tinkerer by nature so I subscribe to the idea that, if I can fix it myself why pay someone else to?

Now about that key.......
It fits into the opening perfectly. And stays in place with no movement either way.
I removed the broken fragment using a 1/8" heavy duty metal and wood bit. Then I ran a screw into the hole that was made. Once the screw took hold the fragment popped right out.
Seeing that the key is a weak point, what would be a stronger option that I could get at the hardware store?
Something that would make worrying about torque at low speeds a thing of the past.

Very glad you were able to get the key out. There's no question the outer key is the weak point of the gearbox. But the key should be more then strong enough to work fine. That said there's a reason why Currie stocks those keys by the ton. The biggest problem is the diameter of the shaft plus it's current condition. I see 2 things you could try. Consider putting in 2 set screws into the sprocket hub with dimples in the shaft to match. The idea is to creat a triangle between the key and the 2 set screws. This will aid in keeping the key in place by pulling the sprocket tight on the key and add in the holding power of the gear to the shaft. This is a common practic used on machinery when dealing with small shafts with key ways that don't allow for a set screw over the key due to the small diameter of the sprocket hub. Second would be to drill a hole straight through the shaft and install a roll pin. I would not go any larger then a 3/16" pin. While the addition of the set screws will be more difficult and time consuming it will minimize the weakening of an already weakened shaft. I would worry that drilling a hold in that shaft may cause it to snap off under load. You will need to purchase a good tap and tap handle plus a good drill bit as needed for the tap size.

Bob

If I remember correctly, the eZip key is a weaker non-Ferris metal - designed to protect the shaft from damage.
If you must ... there are stronger keys at local hardware stores.
Take a magnet and go to the local hardware store.
Look at 4mm keys and make sure a magnet is attracted to it.
Most likely you will need to cut, grind or file key to fit properly, but should hold up much better.

Anywhere near Tampa ? Lots of Trailz and Trailz help over here !

If only. Im on the Sanibel/Ft myers side