Bicycle Motor Refuses to start

GoldenMotor.com

Norman

LORD VADER Moderator
Jan 16, 2008
2,605
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pampa texas
Re: Motor Refuses to start

your key way looks worn/ not right too wide. what does the other part look like and what does the key its self look like?
See the shoulder at the back of the slot that looks like what it used to be in width now it looks like its way to wide this will allow the timing to go to ****.
Did you heat up the shaft it looks like its been hot and the seal looks a little cooked if it is you will need to replace the seal or it won't run right if at all.
 
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toytime

New Member
Mar 20, 2008
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Ontario
Re: Motor Refuses to start

Wow! It looks like you need a new engine.....no just kidding. I'm so happy for you, you have now figured out why it would not start. Your spark plug may have been sparking when your piston was on it's way down.
I think they may sell what I will call "offset keys" for the tuners that want to play around with timing. A little bit of filing on your part to make it fit would work.
I remember my father used to make his own keys with little 4 inch long bars that were made for making keys...(bar stock?)
I won't get into it now but I'm thinking that you now know enough to figure it out by yourself now. You want to make a key that will fill the slot totally, while at the same time, making sure that the parts line up the way they were supposed to. There are other solutions but all of them would involve too much money and time. Seems to me that now that we can get the whole kit for $200 Canadian from Zoom, it is not worth the time and effort.
This shows how hard we can be on our engines when we pop our clutch and stuff. That is why I always treat my baby as if she were my China girl!
Here is a pic of an offset key to give you an idea of what you want to make'
 

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Mopedamauter79

New Member
Mar 31, 2008
254
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Ottawa
Re: Motor Refuses to start

Wow! It looks like you need a new engine.....no just kidding. I'm so happy for you, you have now figured out why it would not start. Your spark plug may have been sparking when your piston was on it's way down.
I think they may sell what I will call "offset keys" for the tuners that want to play around with timing. A little bit of filing on your part to make it fit would work.
I remember my father used to make his own keys with little 4 inch long bars that were made for making keys...(bar stock?)
I won't get into it now but I'm thinking that you now know enough to figure it out by yourself now. You want to make a key that will fill the slot totally, while at the same time, making sure that the parts line up the way they were supposed to. There are other solutions but all of them would involve too much money and time. Seems to me that now that we can get the whole kit for $200 Canadian from Zoom, it is not worth the time and effort.
This shows how hard we can be on our engines when we pop our clutch and stuff. That is why I always treat my baby as if she were my China girl!
Here is a pic of an offset key to give you an idea of what you want to make'
I'm not buying from Zoom. There the same pos that I have. I'm getting one from a guy in thunder bay that sells them.

For the record the pic above isn't a pic I took..This is what is a pic I took with my cell phone to show you what I see now.

I'm STILL not seeing this key you guys keeping talking about. All I see is a shaft with a slot or whatever in it..Nothing even close to looking like a key of any sort.
 

Bikeguy Joe

Godfather of Motorized Bicycles
Jan 8, 2008
11,837
252
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up north now
Re: Motor Refuses to start

The reason your bike won't run is because you have no key!

Find a key at the local hardware store (take the piece you took off with you) and when you put it back together with the key in place, it will run.

Do this now.
 

Mopedamauter79

New Member
Mar 31, 2008
254
0
0
Ottawa
Re: Motor Refuses to start

The reason your bike won't run is because you have no key!

Find a key at the local hardware store (take the piece you took off with you) and when you put it back together with the key in place, it will run.

Do this now.
But it ran before is the thing..They key just doesn't come on it's own. I've never see anything like this key at the hardware store anyway. I wouldn't know what to look for and beside i think the "thing" is bent a little when I had to pry it off. My guess is that it wont go back on very easily. Is it worth the hassle of fighting with this thing on a daily bases trying to figure out why it's not working.
 

Mopedamauter79

New Member
Mar 31, 2008
254
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Ottawa
Re: Motor Refuses to start

Well it definitely doesn't have this key. However I can't tell u when or how it came off. I only opened the cover after I tried everything.
 

paul

Well-Known Member
Dec 23, 2007
5,547
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Kalamazoo, MI
Re: Motor Refuses to start

if the bicycle motor was runing before i would think the key was thier and probably broke or whatever and was lost. i do beleive the key must be thier for the motor to run
 

Norman

LORD VADER Moderator
Jan 16, 2008
2,605
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pampa texas
Re: Motor Refuses to start

No key operations are possible but it requires a tapered shaft and a tapered hub and both need to be lapped together. You have neither so if you want it to run you will need a key to fit the shafts slot and the rotors slot and they should be fairly tight in the slot. The rotor requires a wood ruff key on all my engines it looks like a half moon. If this picture is of your engine it looks to be wallowed out there is a good possibility your engine is done for with the way the key way looks there is ways of fixing it but you talk like you do not have the abilities to do the repairs that will need to be done. I suggest you get someone else to do the required repairs and or purchase a new engine. the one you have will be a tough one for you to fix.
You will need to machine a new key slot you will at the least need a dremel with a metal cutting disc and more likely need to split the case to get enough room to get the tool on the shaft to cut the slot. I dought if you want to tackle that. you might be able to use the damaged key way and hand make a special key to fit snugly on the shaft and the rotor both will take some work and you will not be able to buy the item off the shelf. So its your choice to do what ever you want to it. I will still offer my help but I can't promise I'll be able to make it work.
Take a picture of the rotor and its keyway if you can I'd like to see if its ate up like the shaft.
 
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Bikeguy Joe

Godfather of Motorized Bicycles
Jan 8, 2008
11,837
252
63
up north now
Re: Motor Refuses to start

Norm, he said that was just A picture, and not of his engine....or so I thought.

Still, he needs to put a key in there and go ride.
 

Mopedamauter79

New Member
Mar 31, 2008
254
0
0
Ottawa
Re: Motor Refuses to start

I was sure I posted a picture of the key way ..Anyway I will post the pic again.

Here is the pic I took today with my roommate's digital cam. Oh and I FOUND the key! It was stuck to the magneto.

Pic without the key and a picture WITH the key.

 
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deacon

minor bike philosopher
Jan 15, 2008
8,114
9
0
north carolina
Re: Motor Refuses to start

Question from the villiage idiot... can you use jbweld to hold that key in place if it isn't wallowed out too badly.
 

deacon

minor bike philosopher
Jan 15, 2008
8,114
9
0
north carolina
Re: Motor Refuses to start

My thinking if there isn't too much movement it should help anyway. Maybe keep it from falling out again.
 

toytime

New Member
Mar 20, 2008
550
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Ontario
Re: Motor Refuses to start

My thinking is that sudden stops, like letting the clutch out to kill the engine is what does things like this to an engine. If it was my engine I would try the JB weld and drive with extra care. If that did not work my next step would be to make a custom key that would take care of the extra wide key way. after that I would weld 4 tiny welds with a mig welder to hold it in place and leave the nut off if needed. A weld at 12 o'clock,then 6,3 and 9 o'clock. Yes there is the possibility of screwing up the seal but one weld at a time may be OK. From looking at his pics, I don't think things are as bad as he makes out but it's hard to tell.