I'm trying to thread the chain for my bike but when I try to turn the 10T sprocket it stops after about a quarter rotation. I loosened the spark plug to ease compression, but it still won't move past the one cycle. I'm kinda new to working with small engines in general, so I can't see the obvious solution to this.
Can't figure out my problem.
- Thread starter CaliRebel
- Start date
DaveC
Member
yah, the chain will get a kink in it that prevents the sprocket from turning. Take the clutch cover off, making sure the bucking bar and bearing doesn't fall out of the center of the clutch. It's no problem if the do, just re-grease with the heaviest grease you can find. Now you can easily turn the sprocket useing tools if needed. When you put the cover back on make sure the bolts are tight or use Blue Locktite or sure as shooting the bolts will back out 
.
little p.s.: inside the clutch cover there's a small pin holding the clutch bar in. In racing terms the pin is called a "by Jesus pin" meaning it will hold, by Jesus! Don't trust in deities, carry a 1/2 inch long #3 Metric screw with you in your spare parts bag so when it does back out and disappear you have a way of fixing it. The Chinese glue the pin in so it's prone to failure.
.little p.s.: inside the clutch cover there's a small pin holding the clutch bar in. In racing terms the pin is called a "by Jesus pin" meaning it will hold, by Jesus! Don't trust in deities, carry a 1/2 inch long #3 Metric screw with you in your spare parts bag so when it does back out and disappear you have a way of fixing it. The Chinese glue the pin in so it's prone to failure.
Now I'm not feeling better. The 10T sprocket won't turn more than a quarter rotation even without the chain on. Maybe I really do have a problem...
I can feel the piston moving and bottoming out, but then it just stops. When I reverse the direction it still won't move past bottom dead center. Turning the magneto by hand has the same problem.
Suggestions or questions please.
I can feel the piston moving and bottoming out, but then it just stops. When I reverse the direction it still won't move past bottom dead center. Turning the magneto by hand has the same problem.
Suggestions or questions please.
MotorBicycleRacing
Well-Known Member
Do you have the clutch cover off? {5 bolts right side]
Are the gears jamming, small bevel gear cracked, etc
Look in the exhaust port to see whats going on.
Only other thing could be the crank bearings are seized somewhat
So looking down the exhaust it's actually stopped at top dead center not BDC. The gears aren't jammed either. I haven't taken the head off, but if this as unusual as it sound I might just send it back to the distributor.
To rephrase the problem the piston will only move down backwards. Any more ideas?
To rephrase the problem the piston will only move down backwards. Any more ideas?
MotorBicycleRacing
Well-Known Member
Maybe time to pull the head, it's quick and easy.
Your needle bearing may have exploded and one of the needles
is jamming the piston to the bore.
or
a piece of ring broke off and is jammed in the transfer port.
or
Your crank bearings are partially seized.
or
A ring pin came out
or
the wrist pin circlip came out
I once had a aluminum head gasket that got squashed out so that
a small piece broke off and went down the side of the piston.
Pull it apart and see. Sounds like a gonner anyway.
Now you got my curiosity up......
Last edited:
MotorBicycleRacing
Well-Known Member
That's a happy ending LOL
thanks for satisfying my curiosity, why did you have the head off?
Did you torque it down right?
You do realize that saying retarded is politically incorrect? lol
My most retarded customer made his own exhaust gasket on a new
motor and was so stoned he forgot to cut the hole for the exhaust.
That was a really hard case to diagnose LOL Wasted a couple of hours or so
and didn't figure it out until the next day.
The reguy was getting upset and wanted a new motor.
Do that to your buddies bike and see how good a tech he is....LOL
While I realize some people take offense to certain words, I believe how you use a word is much more relevant than which words you choose. I feel retarded about the engine because taking off the head previously should have made it the first thing I checked. As a personal definition I think of myself as having acted retarded when I didn't meet the standards I would but on an average person, since I normally put myself to even higher standards than that. The major reason I don't give the mentally limited some special treatment is because they are still remarkably capable and the rest of us are still remarkably limited.
Obviously I'm mostly glad it ended up being just my mistake, not an actual failure, but I definitely should have caught that sooner. When I put the head on before I had it at TDC, but I didn't actually try moving the piston with the head loose. Now it seems like an obvious mistake. Part of these kits is the learning experience so I guess it's working. I'm reading a book on two-stroke repair which I hope will help me stay ahead of the curve at least until my first major repair.
Obviously I'm mostly glad it ended up being just my mistake, not an actual failure, but I definitely should have caught that sooner. When I put the head on before I had it at TDC, but I didn't actually try moving the piston with the head loose. Now it seems like an obvious mistake. Part of these kits is the learning experience so I guess it's working. I'm reading a book on two-stroke repair which I hope will help me stay ahead of the curve at least until my first major repair.
I didn't seat the head properly above the cylinder when I tightened the head bolts down. The piston couldn't actually get to Top Dead Center because the head was preventing it from making the slight protrusion that it needed to fully cycle. Nothing majorly stupid on my part, but at least fairly obvious in retrospect.