Hello from Florida

[picklefish]

My name is Robert and I am new to motorbicycling. I'm not very mechanically inclined and troubleshooting is foreign to me. I cooked for a living so following recipes is not an issue. I have the Grubee skyhawk 66cc kit and with help from my Dad we got it assembled and on the bike. Now I can get it to turn over but it wont stay running. There are no real trouble shooting tips included so I came across this forum to learn what to do.

So I have an inclined driveway, I pedal down it to build up speed and pop the clutch and voila it starts to run. Then it dies. I assume its running on what was in the bowl and after reading this forum, I assume its not getting enough gas. Did this happen to anyone else like this, I really hoped it would work perfectly out of the box. lol thats how green I am. any help or thoughts are appreciated.

 

[nightcruiser]

I'm assuming you have the CNS carb if you have a skyhawk...
First off, the fuel tanks when new usually have a lot of crap in them, if you didn't clean it out before you mounted it you probably have things clogged up by now. Check the filter in the top of the fuel valve to see if it is clean, and clean that tank out so it doesn't clog again. I use an inline fuel filter instead of the filter in the fuel valve.
The CNS carb has 3 jets, a main jet, an idle jet and the enrichment jet (which is in place of an air choke), the enrichment jet adds more fuel to the mix rather than choking off air to richen the mix for cold starts. The idle jet is very small and clogs easily, when clogged you will have hard start and rough running at low rpm. So make sure all 3 jets are clean....
The enrichment jet will help the motor start in the cold, but I've noticed the motors typically don't idle well with the enrichment jet open, so make sure the enrichment jet is closing (back off the lever until there is slack in the cable to make sure it is closed).
I am wondering what fuel mix you are using? The manuals typically say 16:1 for break in, thats a lot of oil, I use 20:1 for the first couple tanks, other recommend 24:1 or even less oil. The motor may struggle a bit to run with a 16:1 mix due to the heavy amount of oil. (however, the extra oil is used in break in to make sure the new parts get properly lubricated before you stress them riding hard).
That is a rundown of some basic stuff, give us more feedback and we will try to help you further.... After it starts can you race the throttle and keep her running, or does it die even when you are rev'ing up the motor???

 

[picklefish]

Thank you for your reply I didnt know what to clean it out with. I am going today to get an inline fuel filter for sure as well as NGK spark plug and a real boot for it. lol. I just found this forum today. I think the issue is I am not pedalling fast enough and its bogging down like my old VW used to do when I first learned to drive a stick. I will post progress and pictures later today. It is the CNS carb. I have it mounted on a 26" Schwinn cruiser bike with coaster brakes.

 

[picklefish]

well that was it! I pedaled faster till the engine warmed up and the throttle took over, I made it almost three blocks before the chain came apart, lol. Now what? I need a new master link, any suggestions as to where I can get one of those? Also need a better than stock tension adjuster, Ive seen youtube videos but some detailed instructions would be so huge, a link to an existing forum post maybe, I will try searching. Welding isnt an option for me either lol. Anymore help or advice would be greatly appreciated. I am so happy it was a me problem and not necessarily an engine issue!

 

[2door]

Here's an old thread that still contains a lot of good information regarding chain tensioners. http://motorbicycling.com/showthread.php?t=11815 You can try the Google Custom Search also to find more discussions. Just type in "chain tensioner" and you'll find plenty to read on the subject.

Good luck.

Tom

 

[nightcruiser]

If you have clearance to run a straight loop of chain WITHOUT the tensioner I would tell you to give that a try. I had the same experience with the chain and tensioner, kept causing me problems. Long story short, I moved to a #41 industrial/farm chain shortened to run without a tensioner and that was the end of my problems. Whatever you decide to do you need to get a better chain, the china kit chain is gonna be nothing but problems. Once they fail it seems they fail and fail again until you want to beat yourself with the damn chain!

 

[picklefish]

https://lh3.googleusercontent.com/-...I/AAAAAAAAACo/zF0cxFDUt9g/w497-h373/photo.jpg
Thats what I did. My bike chain was too short so I added a link to lengthen it so I could have both chains at about the same tension. Now without the tensioner to guide the chain the chain is thrown off the srocket. Funny thing is its not that far off, I mean really, a "skosh" is all. gnats hair, but its just enough. I am gonna get a spring chain tensioner and put that on to see if its enough to guide the lower part of the chain into the rear sprocket. what do you think of this issue? that link is a picture of the bike.

 

[picklefish]

the chain was breaking because the engine had shifted enough that the drive sprocket was caterwompus enough to put stress on the side of the chain. I agree that the chain is probably junk and I will look for the chain you recommend. Right now I want to fix this alignment issue and see whats what. Im so jonesin to be able to ride this thing!

 

[nightcruiser]

Proper sprocket alignment is crucial no matter what, tensioner or no tensioner. Your rear sprocket must be centered on the hub otherwise the chain will tighten and loosen as the wheel rotates, and if it wobbles in and out it will want to throw the chain off the sprocket. If you spend the time to make sure the rear sprocket is just right you will have much less problems. You can dish the rear sprocket in or out, whichever way makes the front to back chain alignment better....

 

[picklefish]

what does the term "dish" mean or refer to? The rear sprocket fit over the hub perfectly, seriously zero wobble. but because the coaster brake there is no room to push out the sprocket with shims or them round things with the hole in em.. washers...ha ha, brain fart. and since the deviation is so slight, less than 1/8inch. I think when I let off the throttle theres some shaking and thats whats whipping the chain enough to throw it off. I will post some closeer up pictures of all the parts.

 

[paul]

dish means perfect center which with a sprocket i next to impossible to do. however take your time and center as well as you can and get rid of all the wobble you can. your bike will run faster and smoother

 

[picklefish]

there is no wobble and it fit the hub perfectly, no gaps or extra space, I was amazed because it wasnt fitting on my Mt Bike which was what was gonna get the motor origionally. We are going to reset the tire to see if that fixes it before going to the bike store for a spring loaded chain tensioner.

 

[motortriker]

following recipes is a great skill that some just can't do.

I used to train people how to take machines apart and repair them in a can factory.

The instructions would be right in front us and some people would right away start doing things out of order.

Cooking is great training for this !

It was a new factory an I was told they hired as many people as they could from the restaurant industry because of the fast and logical thinking that one gets from working in a restaurant.

 

[picklefish]

https://lh5.googleusercontent.com/-...AAAAAAAAADE/aUG7DlYU8yU/s605/motobikepic1.JPG
that should take you to the album that has the three pics of the chain and sprocket. I love the way it looks, I love the way the engine sounds when I was riding it. I want more!!! lol.

 

[picklefish]

Thanks for the encouragement, pics are posted.

 

[nightcruiser]

Most sprockets will deviate slightly in one direction where the teeth are, in other words they are not completely flat. They "dish" up kinda like a dinner plate... If installed one way it will move the chain away from center, the other way it toward the center. Installing one way or the other can help prevent the chain from dog legging from the front sprocket to the rear....
As for centering and wobble, spin the wheel and look at the sprocket, it shouldn't bump up and down or wobble in at out at all, or a little as possible...

 

[picklefish]

so is the fix to remove the sprocket from the drive shaft flip it around and reinstall it?

 

[nightcruiser]

so is the fix to remove the sprocket from the drive shaft flip it around and reinstall it?

You have to access the situation, from your pictures we can't see squat. Is the chain running parallel from the front sprocket to back, or does it pull inward or outward as it goes from front to back? If it is doing either of those and flipping the rear sprocket so it is dished the other way will minimize it, then yes, if not, then no. And again, the centering of the sprocket you have to eyeball yourself, spin the wheel, does the sprocket go up and down? Or is it centered perfect? If it bumps up and down, or in and out, then you need to work on it until it is as dead center and even as possible. If you're chain is jumping off you've got something going on that needs correction....

 

[picklefish]

Heres the problem I discovered with the chain being thrown off. the stupid kit chain wasnt exactly the right fit for the sprokets, and without the chain tensioner to provide the tension it would get whipped right off. Its also why the stupid thing kept breaking. I spent $14 on a bicycle chain that was space right and havent had a problem since, I am using the kit chain tensioner as a guide wheel primarily, corrected chain tension with a chain tool and by moving the rear tire back. The bike runs great now!

 

[Legwon]

Heres the problem I discovered with the chain being thrown off. the stupid kit chain wasnt exactly the right fit for the sprokets, and without the chain tensioner to provide the tension it would get whipped right off. Its also why the stupid thing kept breaking. I spent $14 on a bicycle chain that was space right and havent had a problem since, I am using the kit chain tensioner as a guide wheel primarily, corrected chain tension with a chain tool and by moving the rear tire back. The bike runs great now!

good to hear u got it running right

when someone is saying a "dished sprocket" they are refferring to the set of teeth that are flanged out as in the pic here... http://www.ebay.ca/itm/9-Hole-44-To...c-80cc-Engine-Motorized-Bicycle-/370705179139
that sprocket is laying "dish" up.
some sprockets are totally flat, but thats mostly aftermarket. dont think i seen a kit sprocket that is flat.