Small sprocket won't turn - Help!

[reiola]

Hi everyone, I'd first like to say that this forum is amazing and has proven to be a great source of knowledge. I've had to refer to it many times already during my first build.

Information to assist in the problem diagnosis:
Motor: Grubee Skyhawk 66cc
Bike: Schwinn Del Mar
Chain: 415 supplied with kit

Anyways, I am just about done, but am stuck installing my chain. I cannot get the chain over the small sprocket - which won't budge. I've been browsing the forum with the search but can't find anything that deals with the small sprocket being seized up, only clutch adjustments etc. I believe I have the clutch lever and cable assembly set up correctly, nice and tight, it is hard to pull the lever on the bars in, but it seems to be doing its job. I cannot get the small sprocket to turn to allow me to put my chain on, even with my handlebar lever in. Any ideas why? Is my clutch not disengaged if the sprocket won't turn? I read Norman's sticky about the clutch adjustment and I am not sure if it is the clutch causing this problem. Will an adjustment of the flower nut free up the sprocket? What exactly allows the small sprocket to move/not move? Thanks for your time.

 

[Norman]

If your are trying to put the chain on the front sprocket take the spark plug out of the cylinder.
Most engine kits come with a spark plug wrench that has a small socket on one end and the spark plug socket on the big end. Lay the chain on the top side of the sprocket(small sprocket) put the spark plug wrench on the nut that holds the small sprocket on turn the wrench counter clock wise and feed the chain through be careful not to snag your fingers in the sprocket and chain crank the chain on with the wrench. You might be able to get someone to help with this like either crank the wrench or feed the chain if you can problems. Its not hard to do with a little practice.
I didn't tell you but you need to remove the clutch arm cover to do it, put the chain on and to have access to the nut on the sprocket.
Plus your engine is going to be turning over as you crank the chain on that's the reason for the spark plug being removed(easy to crank) you can also disconnect the wires to the cdi if your worried about the ignition.

 

[reiola]

Thanks so much for the quick and detailed response Norman, I got it around and almost on! I'm fooling with the tension and breaking the chain to the correct length. I have regained momentum! I'll probably be back in 5 minutes with another issue

 

[DonnnN]

Thanks so much for the quick and detailed response Norman, I got it around and almost on! I'm fooling with the tension and breaking the chain to the correct length. I have regained momentum! I'll probably be back in 5 minutes with another issue

Good luck with the build and have fun!

 

[reiola]

So I got the chain all set up and the wheel aligned. I set it up so that it is in line and tight without the chain tensioner, but now my regular peddling chain is too loose for comfort. Is there anything wrong with using the tensioner on the peddling chain? My thinking is that if the tensioner fails while peddling the damage will be much less than if it were to fail at high speeds if it were on the engine chain. Any thoughts?

 

[AaronF]

So I got the chain all set up and the wheel aligned. I set it up so that it is in line and tight without the chain tensioner, but now my regular peddling chain is too loose for comfort. Is there anything wrong with using the tensioner on the peddling chain? My thinking is that if the tensioner fails while peddling the damage will be much less than if it were to fail at high speeds if it were on the engine chain. Any thoughts?

That is how I had mine setup with the stock tensioner on the pedal side chain it worked fine!

 

[reiola]

Alright, I will try to put the tensioner on the peddle chain tomorrow, thanks for the info AaronF! I will try to post pictures of the build/progress as well.

 

[Dan]

So I got the chain all set up and the wheel aligned. I set it up so that it is in line and tight without the chain tensioner, but now my regular peddling chain is too loose for comfort. Is there anything wrong with using the tensioner on the peddling chain? My thinking is that if the tensioner fails while peddling the damage will be much less than if it were to fail at high speeds if it were on the engine chain. Any thoughts?

Howdy Reiola. The new engine chain is going to stretch. You need the tensioner on until it does. Or am I misunderstanding? Is late and I have been awake to long.

 

[spit_fire]

if your regular chain is to loose you can always use a chain breaker tool to take out segments of your chain to get it just right if its going threw a derailer you cant use a master link as it will jam in the derailer but if you got the litle tool wich is cheap like 5-10 bucks you can push the pin back threw the link to connect the chain again once you have the preffered lenght

 

[Predator303]

Is there a way to get the chain OFF without opening the nut? I tried it and it always get stuck somewhere. I dont want to damage it. I just bought it new but I need to change the whole bottom end.

 

[dragray]

you guys are killing me! (just being sarcastic)
first of all, if the small sprocket will not turn with the clutch handle squeezed in, then either his clutch plate is stuck from rust (sitting too long) or his clutch is way out of adjustment.
if the clutch is correctly adjusted and not stuck, the piston WILL NOT move up & down while you turn the small sprocket. actually if the clutch is free and adjusted right, there's no need to even remove the spark plug because you will not be turning the engine over...so there will not be compression resistance on the sprocket.
The sprocket should turn but the piston should NOT be going up & down.
If this was the case, you'd be turning the engine over while peddling with the engine not running.

You can feed the chain in under the clutch cover(without having to remove the clutch cover). If the clutch is adjusted right and not stuck, you can feed the chain in under the cover, on top of the sprocket. Then, you can use a screwdriver to rotate the sprocket by the teeth, which will pull the chain around it and out the bottom...no need to remove the cover.

He does not have a derailer(as someone mentioned) because if he did, the derailer would automatically adjust the tension on the pedal chain and there would be no need to put the tensioner on the pedal chain.
it sounds to me like he has his engine chain way too tight already.
there is no way to get both the engine chain and pedal chain at the right tension without using a tensioner or a 1/2 link.
now, he can put the tensioner on the pedal chain with no problems, but...i think the fix is to use a 1/2 link on the engine chain to get both chains to be at the right adjustment.
you can run these bikes with no tensioner at all on either chain, but it takes time to get the chains right....by using 1/2 links.
without 1/2 links, you will always have one chain too loose, and one chain too tight.
you want at least 1/4 - 3/8 inch of up & down play in the engine chain. any more than that, & the chain will pop off. if it's too tight, the chain can break.
setting up a bike so that both chains are at the right adjustment is harder than it sounds unless you have an idea of how to do it.
sure, you can use a chain breaker to remove links on the pedal chain, but i gurantee you that when you remove one link (which is actually 2 links) the chain will be too short at that point. This is why you need 1/2 links. this will allow you to re-connect the chain with 1 link less than what you removed.
it's hard to explaine, but if you've ever used a 1/2 link, you'll know what i'm talking about.
they make 1/2 links for the pedal chain and for the engine chain.

When you break a chain, you end up with 2 different ends (an inner and an outer link). the only way to re-copnnect these ends is to put back 2 links(an inner and an outer).
when you break a chain, this is what you end up with. a master link won't work unless you have an inner link on each end of the chain, which will require removing an extra outer link, which will still make the chain too short. In that case you would have removed 3 links of chain.

after removing a link (which consists of an inner and an outer link, 2 peices) the chain then becomes too short by a 1/2 link. So the only way to make the chain the correct length is by adding a 1/2 link (which you can not do with regular peices of chain that you already removed.)
so, you need a 1/2 link to connect the ends back together to give you exactly one link less in the chain.
here's a 1/2 link.
look at it and look at the chain that has been "broken" above, and you'll see why these 1/2 links are so helpful.
I'm not trying to say that I know everything, because i don't.
I'm just trying to share my knowledge.

 

[Dan]

We are all just students in varying degrees of experience.

 

[Predator303]

I agree......

 

[porkchop]

chain problems...
hi all noob here to,i completed my build took for a test ride broke the chain,went to bike shop they made a new chain the length i needed,installed it this morning took for another test drive...this chain snapped too.i've checked & double checked alignment seems fine...

 

[Predator303]

get it installed in a shop then because something must be wrong obviously..

 

[Dan]

Howdy PorkChop. Welcome.

If it is lined up, I would check the tension. Roll it forward a bit so the top of the chain is taunt. Then it should have about 3/4s of an inch up and down wiggle room with out really forcing it.

Please know this is just what I do and there may be a lot of other thoughts on this. Can get confusing but that is what I do.

 

[Dan]

LOL Lowrider. We were must have been typing at the same time.

Didn't mean to sound like I was disagreeing with ya.

 

[Predator303]

dont worry i didnt even see it that way

 

[porkchop]

Dan,thanks for the info i was thinking about that to & i might have to use a heavier chain i'm 250 lbs...this cheap tensioner they give with the build i'm not sure how long that would last..lol..pretty light

 

[Predator303]

Is there a way to get the chain OFF without opening the nut? I tried it and it always get stuck somewhere. I dont want to damage it. I just bought it new but I need to change the whole bottom end.