Troubleshooting engine start fail

[Nahom]

Ok- I've now practically replaced everything on the bike I originally bought and still it fails! I just don't understand... there's so many variables it's driving me insane

I went to this page: http://motoredbikes.com/threads/wont-start-have-spark-and-fuel.39525/
and did everything that was suggested bar a couple that I couldn't do.

The only thing I haven't done is check the magneto loop. I can't do that because the screw was in so tight and now one of those 4 is stripped so wont come out so the case won't come off (It's too deep in too). I have no choice but to go buy a hacksaw and an anglegrinder tomorrow and cut the case and screw off and then replace with case of old engine.
I also don't have starter fluid so I will buy some of that tomorrow.

I was hoping if someone could kindly answer me the following questions one by one please:
1) People in other threads keep talking about assembling the magneto loop with a new engine- I swear it was in there already when the kit arrived. The fact that there is a spark when I hold the plug to the outside fins of the cyclinder means it's there surely?
2) I switched blue with black to see if there was timing error. It didn't start. I did the plug to fins test and still there was a spark! So how can I know which way around it is?
3) My tank is half full with 20:1 fuel ratio. How do I add the starter fluid? Put it in with the current mixture? Empty the current tank and put starter fluid only?
4) If it's a flooded engine do I have to pedal with the plug out or can I just leave the bike with plug out and wait for fuel to evaporate?
5) Was the bike supposed to start just by releasing the clutch after pedalling? When it worked what it would do was only start after I'd released clutch, kept pedalling AND twisted the throttle. Otherwise no start if no throttle twist. If I let go of the throttle it would just stop - I needed to keep some gas with throttle. Is this how it should be?
6) If turning idle screw clockwise (tightening) makes the engine slow why would I need to try that in order to help it start?
7) I don't really undertstand post number 4 by Al. Fisherman in this thread: http://motoredbikes.com/threads/engine-wont-start-yes-ive-searched.29554/
What is the difference between the first two pictures? He says: "Here you can see the cutaway for the key. Only seen after removal of the magneto."
And in the second "Here is the key installed. When installing key and magnet, super glue key in place, this makes for a much easier instillation of the magnet." It seriously looks as if nothing's changed.

cheers

 

[commanderroach1999]

STOP DON'T USE STARTER FLUID u don't need it! First of all the correct fuel ratio is 16:1. second only connect blue to blue and black to black. third if u got spark don't worry about the electronical stuff.Forth ur engine isn't flooded and don't ever ever pedal or spin the wheel unless the spark plug and the cdi are hooked up, I made that mistake and I ended up buying a whole new cdi.Fifth on the throttle cable on the carburetor raise the hight of the throttle cable, also turn the idle screw clock wise and every 360° try the motor again until it is to ur liking. sixth the Isle screw is what raises the throttle in the carb so when u lay off the throttle it won't shut off the engine completely. if u are getting spark don't touch the electrical stuff, if u are getting fuel don't touch the fuel stuff, so u must got a compression problem. check the clutch case. make sure the clutch plate spins without turning the gear when the clutch is held in. when u release the clutch the gears should spin. if the clutch is ok you need to remove the magneto magnet and adjust the little half moon (woodruff key) so it will turn the gear. if the magneto side is good check the small gear on the clutch case and remove the small gear and check the halfmoon (woodruff key) and make sure it turns the gear.

 

[crassius]

buy a hand impact driver to get that screw out - it's a cheap, handy tool you'll need a lot

when starting motor, one pedals up to a good speed, then EASES out the clutch while still peddaling until the motor takes over

if you see spark, ignition is probably all good

 

[Nahom]

Beautiful I'm gonna buy an electric drill, hacksaw set, angle grinder, hand impact driver from homebase and get to work on all these things! thanks .
But firstly how can you be sure the engine isn't flooded ? fuel tap on the gas tank was turned on when it I tried to start and fail many times- some unburnt fuel would surely have reached the carb and therefore engine?

 

[Nahom]

buy a hand impact driver to get that screw out - it's a cheap, handy tool you'll need a lot

when starting motor, one pedals up to a good speed, then EASES out the clutch while still peddaling until the motor takes over

if you see spark, ignition is probably all good

Hi Crassius I googled hand impact driver and I can't see how it will work for stripped screws if you have specific screwdriver heads. My screw head is do stripped it doesnt even form a perfect circle it's this weird blob kind of shape.

 

[crassius]

as long as there is some amount of slot remaining, the force of hitting with hammer will give it a bit of grip - I sometimes just smack the bit real hard with the hammer to set it in good before putting the driver part on the bit

 

[Nahom]

as long as there is some amount of slot remaining, the force of hitting with hammer will give it a bit of grip - I sometimes just smack the bit real hard with the hammer to set it in good before putting the driver part on the bit

Ok sure thanks-
Is something like this adequate? : https://www.cromwell.co.uk/shop/hand-tools/screwdriver-bit-handles-and-sets/40-pce-impact-driver-set1-2"-sq--dr-/p/KEN5737140K?utm_campaign=pla+-+&utm_source=google&utm_medium=shopping-pla&utm_keyword=KEN5737140K&istCompanyId=6aa6787b-063e-4414-802d-129f235df603&istItemId=aqrxqxirx&istBid=tztx

Also if I kept touching the metal parts of the spark plug on both ends with my finger is that bad?

 

[Nahom]

...

When the the clutch is held in only the big gear with the clutch plate spins. When the clutch is out- the big gear wheel and the small gear wheel both move. Is this what you meant should happen?

 

[Steve Best]

Your fingers cannot hurt the sparkplug, no worries.

You have spark, good! no more worries about your magneto.
How about the timing? Did you have the rotor off?
If you did make sure it was put back on with the key at the 1 o'clock position.

So, you have spark and spark timing. Do you have compression?
Will the engine compression drag the tire as you push the bike?
If it does, good.

Spark, spark timing, compression, what about fuel?
It is in the tank, does it flow to the carb? Pull the line off at the carb and check. Yes?
Gas to the carb is good. Undo the screw at the bottom of the carb to see if fuel dribbles out. Yes?
So put the choke on and pedal. Let the clutch out, THUP-THUP-THUP. Open the throttle a bit. Anything?
Try it a couple times.

If nothing, pull the plug out and smell it. Gas/petrol smell? Wet or dry?
This tells if too much or not enough gas.

Tell us where you are at this point?

Steve

 

[Steve Best]

When the the clutch is held in only the big gear with the clutch plate spins. When the clutch is out- the big gear wheel and the small gear wheel both move. Is this what you meant should happen?

The big gear and little gear are meshed together. If one turns, they both do.
When you hold your clutch, the sprocket side disconnects from the big gear by the plate in the center of the big gear.