Please Help Got spark got petrol..Engine will not start

[Al.Fisherman]

thats great man im glad u got it running again theres not much worse than the frustration of having an engine that wont run and especially to find out that its something as small as this but its good to hear it runs again,good luck on any issues in the future but on the plus side to all my frustration i now know alot more about about the engine than i ever did before now all thats left for me is to get it apart and make sure that my problem too and then find where to buy the key

If your key is the culprit you can get them online from a vendor, or to to auto parts store. They have a assortment, if they don't have the correct fit, buy a larger one and file it to fit. The key is softer then the crank, this enables to shear..I have never had one shear.

 

[azguero]

ok so i pulled it all apart again,couldnt get the magnet off but used a flashlight to look into the notch and the key is in there but still no rotation

 

[Al.Fisherman]

ok so i pulled it all apart again,couldnt get the magnet off but used a flashlight to look into the notch and the key is in there but still no rotation

For there to be NO rotation, one of these things needs to happen. The crankshaft is not turning, a broken crankshaft ( I doubt). Remove the spark plug, while in gear push the bike. Two things I'm sure will happen...one the piston will cycle (up and down) and the shaft where the magnet (on the crankshaft) will turn, will do even with or without the magnet. If so the key is stripped. That is the ONLY way a magnet won't turn. Once the nut and washer is removed you need to carefully pry the magnet off.



http://s982.photobucket.com/albums/ae309/Ron-Becker/Chinese HT breakdown/?start=0

 

[azguero]

the piston is moving up and down but no rotation on the magnet i saw the key but i can try to pull it off im just not a very gentle person and didnt want to break it but ill keep trying and everything else is moving i can see the shaft behind the gear on the clutch side moving but couldnt see the shaft to the magnet moving and if it is the crankshaft its pretty much trashed right

 

[Al.Fisherman]

the piston is moving up and down but no rotation on the magnet i saw the key but i can try to pull it off im just not a very gentle person and didnt want to break it but ill keep trying and everything else is moving i can see the shaft behind the gear on the clutch side moving but couldnt see the shaft to the magnet moving and if it is the crankshaft its pretty much trashed right

I'd bet that the key is FUBAR. But as you say the clutch gear moves then the magnet shaft will move. If it is sheared (crankshaft) it will be just inside the case, and use your engine as a decoration. I wouldn't recommend you to replace the crankshaft (if it's broken) due to your limited mechanical skills. Not to put you down, but some HT owners don't have the skills, as you can see by the number of "HELP" posts. These are the simplest engines that I have ever worked on, bar none.
Also the worse built.

 

[azguero]

i just took the plug out and the magnet started spinning(sometimes) but i put it back in and it stopped again this thing is just evil is what it is

 

[Al.Fisherman]

i just took the plug out and the magnet started spinning(sometimes) but i put it back in and it stopped again this thing is just evil is what it is

I'm telling you it's the key.....period. Do you still have the coil installed?

 

[Al.Fisherman]

azguero

Lets take this into the chat box.

 

[azguero]

ok so i was wrong i took the cylinder head off again and the piston ONLY spins when the magneto spins and it spins sometimes but other times it just make a clicking sound but the whole right side of the bike still spins im assuming the only other thing there is the crankshaft but i dont see how it could have broken so soon and i dont even know if they warranty them at all so im probably out 180.00 and this will most likely be my last engine i have three kids so theres no extra money around and cant sell a trashed engine so good luck to all on the site i hope all goes well

 

[Al.Fisherman]

Sorry it wasn't the key. If you have a broken crankshaft it will be the first that I have heard on these engines, on two forums. Working on cars I have seen a broken crankshaft, so it's not far fetch but quite uncommon. So it does happen.

 

[GearNut]

Are you sure it is not a broken key on the crankshaft gear or the clutch hub?
I too find it extremely hard to believe that the crankshaft has broken.
Please don't give up on your engine when the problem could be a $1.00 key.
I am also betting it's a failed crank shaft gear key.

 

[azguero]

i dont know man it just doesnt make any sense i have torn it down to where it wont tear down any more and the only thing left is the shaft i have found three key ways and three keys and all are there and look good i finally got the magnet off and i put pics in my album i dont know how to put them on here

 

[azguero]

and what really throws me is that when i remove the plug the shaft will spins intermittently but the second i put the plug back in the mag shaft locks right back up

 

[GearNut]

Job well done on removing the parts for inspection.
I looked at your pictures, there is one more key, where the clutch hub attaches to the transmission shaft.
You are using the stock spark plug? Is the spark plug hitting the top of the piston?
Does the tip of the spark plug show any signs of hitting the top of the piston?

If all the key ways, keys, and gears are good, if the spark plug is good, if the clutch is not slipping, then everything should be fine.
Breaking the crankshaft or transmission shaft could only be the other faults, and I highly doubt that either of those has happened. They are made of very strong steel.

 

[Al.Fisherman]

Job well done on removing the parts for inspection.
I looked at your pictures, there is one more key, where the clutch hub attaches to the transmission shaft.
You are using the stock spark plug? Is the spark plug hitting the top of the piston?
Does the tip of the spark plug show any signs of hitting the top of the piston?

If all the key ways, keys, and gears are good, if the spark plug is good, if the clutch is not slipping, then everything should be fine.
Breaking the crankshaft or transmission shaft could only be the other faults, and I highly doubt that either of those has happened. They are made of very strong steel.

I also find it hard to believe that the crankshaft broke (but I have seen them before) I also find it hard to believe that trying to pull the magnet off the shaft that there was no tell tale of a broken shaft. One more thing install the nut on the magnet shaft and if you have a drill spin it without the plug installed.


As long as this shaft turns, the piston will rotate. This will eliminate the gearing in the clutch (2 sprocket..2 keys) and the drive sprocket (1 key). Then we can go from there. Doing this without the head installed would be better.

 

[azguero]

when i spin that shaft the piston moves but when i put it all back together the shaft only rotates occasionally and with the plug installed never and i have two plugs and have tried them both i want to get a new ngk plug but have no extra cash and at this point it wouldnt make sense to spend money on something that may never run again

 

[Al.Fisherman]

when i spin that shaft the piston moves but when i put it all back together the shaft only rotates occasionally and with the plug installed never and i have two plugs and have tried them both i want to get a new ngk plug but have no extra cash and at this point it wouldnt make sense to spend money on something that may never run again

This has me by the short hairs. I know that I could let you know whats wrong within 5 minutes if I had it...but. So starting at this point is not a issue...it's moot.

Correct me if I'm wrong.
Without the head on the engine and you rotating the magnet shaft the piston rotates 100% of the time. If so then you have a problem with 1.head 2.spark plug 3.gasket, nothing else can be in the way. What did you gap the plug at and what is it now?

With the head on it rotates "occasionally". Are you rotating it in ONE direction and one direction only. NO clockwise and counter clockwise. Either direction will be fine but only one.

You are not telling or explaining to us something we need to know. We'll keep working on it.

How about some pictures of the inside the head, the spark plug and gasket.

 

[azguero]

ok so when i turn the mag shaft manually the piston pumps EVERY time and when i push the bike the shaft will turn occasionally but when it turns the piston pumps and as the pics show i cant take anything else off without opening the engine but it seems that i should NOT open the engine myself but it seems like the problem lies inside the engine i will try to get some pics up of the head off tomorrow after work like i said i have tried EVERYTHING mentioned on here but i think gearnut said there was ANOTHER key? i have found three should there be a fourth? and yea it would be soo much easier if you could see it in person but theres not much more that can be tried i dont think

 

[azguero]

and when i push the bike it makes the mag shaft turn clockwise if looking at the ma side of the bike so i turn it clockwise so like i said it seems as though there is an issue with getting the gear on the clutch side to properly spin the mag shaft

 

[Al.Fisherman]

ok so when i turn the mag shaft manually the piston pumps EVERY time and when i push the bike the shaft will turn occasionally but when it turns the piston pumps and as the pics show i cant take anything else off without opening the engine but it seems that i should NOT open the engine myself but it seems like the problem lies inside the engine i will try to get some pics up of the head off tomorrow after work like i said i have tried EVERYTHING mentioned on here but i think gearnut said there was ANOTHER key? i have found three should there be a fourth? and yea it would be soo much easier if you could see it in person but theres not much more that can be tried i dont think

so when i turn the mag shaft manually the piston pumps EVERY time This eliminates a broken crankshaft..now we are good on that.

when i push the bike the shaft will turn occasionally but when it turns the piston pumps Now I think we are working on a bad key.

If the engine is running these things WILL happen.
1. The piston moves up and down.
2. The crankshaft will rotate.
3, Both shafts on the crankshaft will rotate. On the left side we have the magneto, and on the right side you have the small gear in the clutch.
4. As the small gear turns, so will the large clutch gear.
5. When the large gear turns so will the shaft it is mounted on.
6. As the clutch shaft rotates, so will the drive sprocket (where the chain is driven by) All this will happen, but the chain drive gear won't turn with the clutch disengaged AND weight on the bike..if the clutch is adjusted properly. Without the chain on the chain drive gear it should rotate all the time.

Should ANY one or more keys are not in place, this whole process breaks down.

Now when you rotate the magnet shaft, (the piston will move up and down) The small clutch gear will rotate. To check the small gear, take a piece of wood, or soft metal and jam the gears while turning the magnet shaft.
Here at the large arrow.

If that key is broken then the small gear will spin on the shaft.. If it won't budge on to the next step. Now if when jammed and the small gear won't turn, its time to test the key in the large gear. With the two clutch gears jammed together, rotate the 10 tooth drive gear (it drives the chain). If all keys are ok then I'm looking at the clutch for the problem.