Bicycle Motor Refuses to start

Re: Motor Refuses to start

I hate to jump in here and add my two cents after you have had so many members trying to help you. Someone mentioned to you that if you put a little gas into the sparkplug hole the bike should start. It is true, I would bet that this bike would start with the carb off the bike by putting fuel into the sparkplug hole.
If there is a broken KEY on your magneto (left side, front cover) the engine MAY spark but at the wrong time.
Also, in my snowmobiling days, I found that a sparkplug would spark when out of the engine but under compression, it would not start or even fire up.

Re: Motor Refuses to start

The answers you ask for have been answered but I can understand your frustration and also understand that you are feeling "lost". The reason it may not fire when you put gas inside the sparkplug hole is because you may have a broken key. You may be sparking at the wrong time, like when the piston is at the bottom of it's travel. The cover you want to take off is next to the one you took off. It has 4 bolts holding it. Under there you will find a round thing . if you spin it, the engine has to turn as well .I will try to find pics for you and will post them for you

Re: Motor Refuses to start

Here is a pic that member Norman posted with the cover removed.
Here is a link that may help you to see the magneto. See if yours is "fried".

YouTube - Magneto Install

Re: Motor Refuses to start

Magneto....that is what gives you power/electricity for your spark. It may have a blue, white and black wire going to your CDI box

Re: Motor Refuses to start

Some of the guys have had issues with the clutch slipping so that the engine was not turning when the clutch was released. but if you pedal the bike and the piston is moving up and down I can't see that being the problem but someone else would know better.

Re: Motor Refuses to start

I agree with Deacan, All is good with clutch and you are getting off track. Please make sure you don't get dirt inside the cylinder with your "cover",as you called it (Head) off.
You said at the beginning of this thread that the bike was running until you changed the sparkplug. Lets start all over again. Inside the CDI.(little black box) there is what looks like a nail or screw.....that is what your sparkplug wire screws onto. Hold the box with one hand and with your other hand, unscrew your plarkplug wire from the box. Don't be afraid, just turn the wire to the left and pull at the same time. Now get a pair of side cutters or snips and cut off a half an inch from the end of the wire.
You should now see a nice clean wire in the centre. As you screw the wire back in place (onto the CDI) ,try to picture that nail/screw poking into your sparkplug wire and making contact with the centre of your sparkplug wire as you turn right and push inward.
Now do the same with the other end..(sparkplug end). It also has what looks like a nail or screw sticking out.
Having done this, we hope that you have a good electrical connection going from your black box to your sparkplug.
Now put your head..(your "cover", as you called it ) back on the engine and remember to tighten the four nuts in an X pattern...as in...Tighten the 10 o'clock nut, then the 4 o'clock nut, then the 2 followed by the 8. Do this at least three times as you are trying to tighten the head down evenly without warping the head. I hope you were able to follow that...lol.
Now see if you are getting a spark....if not, we are back to seeing if your KEY is broke and as you were told earlier, you will have to remove that nut and look to see if the slots are both in line. When a Key is installed half of the key slides into each part.so that there is only one way for the two parts to be put back together.
Sorry if any of this was hard to grasp, but it's hard to tell a person what to do in words.
The sad part is that if the moter was in front of most of the members here, we would have it running or at least be able to tell you what your problem was, in 15 minutes

Re: Motor Refuses to start

Mopedamauter79 said:

That's what I thought it was. It does not look dead or fried. looks normal to me. You can't always tell just be the way they look.Just for kicks I removed the cover where the spark plug sits. I can clearly see the piston ? moving up and down. I can make it move by turning that thing beside the Magneto and it even rotates around when I left the back wheel up and pedal the bike. That's all normal, you removed the head and saw the piston going up and down.

This may seem very lame..However I and my roommate thought of a theory..Could my clutch arm be in or out to much and thus the motor is stuck in neutral sorta a speak?? The clutch can be slipping, but if you have the whole works together and pedal it and when you let out the clutch, the engine turns over making an engine sound but doesn't fire up, then the clutch is not slipping.

Click to expand...

Have you ever run this engine?

Re: Motor Refuses to start

The sad part is that if the moter was in front of most of the members here, we would have it running or at least be able to tell you what your problem was, in 15 minutes

Not me I'm the worst novice here. But I was riding down the road yesterday and my NEW spark plug wire came out of the black box. The bike just died. Hard to say what is going on.

Re: Motor Refuses to start

Are you having the same problem I did, ie you have spark when the plug is out and no compression. But with the plug is in and with compression your clutch is too loose to turn the motor over. Are you hearing the motor turn over when you pop the clutch? It should almost sound like it is running. All I had to do was tighten the clutch.

Re: Motor Refuses to start

Deacan,
I wonder if your new wire is the kind without metal wire in the centre? I went to a small engine repair shop and he had a spool of the real stuff. Most automotive stuff is carbon fibre and that would not be held in place. Other than that I use a hot melt glue gun to seal it up at both ends. this really helped/stopped snow and splash from cutting out my motor. That hot melt stuff really works and I promise you that you will never have that problem again.

Re: Motor Refuses to start

Geez Mopedamauter, it really bothers me to see you having such a hard time.
This thread is getting so long now that it is getting hard to follow.
So you got the nut off, now that "whatever u wanna call it" has to come off to see if the key is broken. I guess you could clean it well and see if the keyways are lined up. If they are, I guess you could say that the Key is OK.
Do you know what a key looks like? Let's start there..OK?

Re: Motor Refuses to start

Spray some penetrating oil on the place where the shaft and the "thing" meet and wait for a few minutes.

Find two pieces of wood that will wedge under the "thing", put the nut back on that shaft to cover the threads, and TAP the end with a hammer. The "thing" should come loose.

BTW- You are getting plenty of fuel to the cylinder from your explaination.

Re: Motor Refuses to start

I have included a few pics to help you understand. The key is less than a 1/2 inch long, it's just a tiny little "key" that slides into the keyways so that the flywheel (the "thing" you want to remove) slides onto the shaft (which also has a keyway).You may notice that the keyway is damaged in the second pic.
The first and forth pic is what you want to remove, but keep in mind that these are not pics of our motors.
Another way you can remove your flywheel is to follow bikerguys advice but I will add this: make sure you wind the nut onto the shaft until the face of the nut is even with the head of the shaft. This is so that you do not mushroom the shaft as you hit it with a hammer. With your left hand, hold onto the flywheel so that you are holding the whole bike up so that as you tap the nut, the weight of the engine helps you in removing the flywheel. His wood idea is doing the same thing as it is putting pressure upwards,sort of pushing outwards. The reason the flywheel seems stuck is because the shafts are tapered (cone shaped). As the parts are tightened up the shaft tighten up on themselves. You are trying to give it a good shot with the hammer so that the shock breaks it loose. You could also try to find a "puller" as this is what they are made for.