new engine but wont start

[azguero]

hi i am new to the motor biking community i recently purchased a skyhawk gt-5 66cc, it was running great and i was using it to go to and from work each day because pedaling 20 miles each way was getting old, the bike was awesome and i rode it to and from work each until one day when coming home which was only like the sixth ride i thought the clutch was l slipping because the engine was on but it was losing speed fast so i assumed it was the clutch but after tearing most of the engine apart everything seems to be spinning,except for the magneto,now does the magneto spin the second the rest of the bike spins and is now bad or is it a delayed effect i cannot get my bike to kick on even though the piston moves up and down freely and nothing else seems to be wrong except when i release the clutch i get no pop at all from the magneto or the spark plug or anything and also why would it be having problems already with it only having about 100 miles total on it if that any help would be greatly appreciated sorry i dont know much about engines and am at risk of losing my job over all this

 

[Norman]

If your magneto is not spinning with the rest of the engine. Take the magneto rotor off there is one bolt holding the magneto rotor on but, first remove the magneto coil 4 screws hold it on. once you have the magneto rotor off it should have a key to lock it to the crank shaft. If that key is missing then you need a new key. Might be the key sheared or some how came out. A tiny dab of super glue will hold the key in place when you re install the mag rotor. the key will try to come out of the keyway and stick to the magnet part of the magneto rotor if you don't glue it in place. You might want to look at the stickys on engine tear down first to get an idea of what you will need to do.
I had a hard time trying to understand what your problem is with your bike but I think your key is missing or sheared.
The magneto rotor is keyed to the crank shaft. If the magneto rotor key is sheared or missing then the engine will not fire at the proper time. you need to remove the magneto coil first so you won't damage the coil trying to remove the magneto rotor which can be a turd to remove , a real turd if the key is sheared and has it jammed on the shaft. sometimes the rotor will come off easy most times you have to gently work it off the shaft. If you get rough with it you may break off the shaft and then your engine will be trash.

 

[Al.Fisherman]

Pictures coming up...

You say...i am having a similar problem with mine. Does this mean you still have the same issue? If so, there is a cutaway in the shaft where the magnet sits over the shaft. Your problem may be that (since it was running) the key sheared. Remove the magnet by removing the nut, and working the magnet off. This mat be a little hard. Inspect the key and the cutout where the key slips down into. You might just need a key. When installing the key, clean shaft (throttle body cleaner works wonders) and drop a few drops of super glue in where the key goes. Set key in place and let dry. This helps installing the magnet as without the supper glue the magnet will want to pull the key out of place.

Picture of key way.


Picture of key.

Check this post out. 2 pages
http://motorbicycling.com/f34/please-help-got-spark-got-petrol-30820.html

 

[Norman]

guess I should add there is 2 ways for the magneto rotor to fit on the shaft. A wrong way and the right way. The right way is with the key way straight up on the shaft, install the magneto rotor with the slot in the hole pointing to the right, the slot isn't off set that much sort of looks like the guy who cut the key way was on drugs or not enough drugs? as the key way isn't true to the hole?!
But the slot does sort of favor the right side of the hole. If you do install the magneto rotor backwards it will still spark but the spark will be at the wrong time and the engine will not run or run very well if at all. so be sure to check that you install the rotor properly.
You can make a set of spacing shims from your favorite beverage can to help center the magneto coil to the rotor. nothing fancy just a couple of strips about 1" wide and a couple of inches long. With the rotor and coil in place have the rotor set so the curved surfaces one at the top and one at the bottom.insert the shims between the rotor and the coil tighten the screws on the coil and then remove the strips. Lot of guys don't bother with this but some do. Doing the install with the shims will help to aline the rotor to the coil so nothing rubs.

 

[Al.Fisherman]

Norman, I covered the magnet in this post
http://motorbicycling.com/f34/please-help-got-spark-got-petrol-30820-2.html

Did not answer the question...The magneto consist of two parts. First we have a magnet (this sits on the crank shaft, with a key way) and a coil. The magnet can be put on two different wary, enabling you to get a spark, just at the wrong time (you had to remove this to install the seal). The coil can be put on upside down, but kind of hard to do as the wire round section is offset to the outside. Blue wire on top and white wire at the bottom. Did you check out the photos I gave a link to?

This is the CORRECT way that the magnet is installed. Notice the upper and lower flat side are East to West. Install the magnet when the piston is at TDC



This magnet is installed INCORRECTLY. Notice the angle of the flat side.

 

[azguero]

thank you very much for all the help i cant wait to tear into it and see if i cant get it running again sometimes you just forget how much of a pain a 20 mile hike each way is until you have to do it again i just hope i dont break anything