This will probably be a fundamental problem for the pros here

[cwicher10]

I bought a motorized bicycle from a guy on ebay, and sadly I wish I would have gotten a kit and done it myself in order to better learn about all the functioning parts. The bicycle was shipped with the motor mounted and everything besides a couple wires and other basic parts to throw on. (Chain was on as well)

After I got the bike assembled, I took it out for it's first start up outside. I played with the choke, primed, and went down a hill for the start. As soon as I let off the clutch, the motor turned over and then then chain almost immediately jammed on the sprocket (assumption) and I came skidding to a halt. A simple backwards roll released the chain. I tried a couple more times and got the same results.

I walked the bike back into the garage and played around with the tensioner a little bit. I made it a tad bit more snug thinking that it had too much play and was getting jammed because of it. I took it back out and got the same results. This ****ed me off and I threw it in the garage and haven't touched it until the other day.

I love the concept of a motorized bicycle and want to invigorate my motivation to make it work. Since I gave up on my initial attempt, I've managed to misplace the tensioner that came with it, and I'm not sure of where to get another one that's compatible. All that's left of it is the bracket that it bolts onto near the chain to push it up.

I'm at a crossroads, because I want to look for another tensioner to order so that I can troubleshoot more with the bike, but I never figured out why the bike was jamming and skidding to a stop on every start up attempt. I'm not a "bike guy" at all and I'm new to all this, so any information that will help me sort this out and enjoy this concept would be amazing. I realize I'm probably leaving out much needed information, so just ask away and I'll do my best to comply.

Thank you ahead of time for the help.

-Chris-

 

[cwicher10]

Forgot image links...

Please ignore the make-shift tensioner

I was trying to get the tension functional so that I could troubleshoot on the locking up issue, although considering my theory of it being the tension causing it.....yea nevermind I just need some guidance haha.

 

[5-7HEAVEN]

Does the engine turn over by hand?

 

[professor]

I do not have one of those kits, but that tensioner is a world of problems from what I have read here.
Many guys get rid of it by shortening the chain (maybe using a 1/2 link if necessary). If you keep it- it must be made so it cannot possibly move into the spokes.
When you let the clutch out to spin the engine -that load goes directly onto the tensioner.
If it were me, and I wanted to keep it- I would weld it to the frame tube or make a bridge part to connect the tensioner bracket to the frame tube above it.

 

[rich2484richard]

ok first need a location. uk, america, europe. so anyone near you can reccomend a parts store. here are a few things to try.

remove the sparkplug and let the clutch go, should be able to push the bike and hear the engine turning over. do this for a bit. if it does the problem then the engine if knackerd.

remove the chain and clutchplate and try turning the gear by hand. if this does not work remove the clutch from the other side and then check again, if engine turns without clutch then the clutch is to blame. but unlikely.

looks like a big engine any idea how big. looks about 70cc to me. mine takes a bit off speed to turn as its 70cc and new.

 

[gearhead222]

Just my dollars worth, but the swinging rear section with the monospring shock absorber cannot be good, as you WILL get varying tension on the chain with the same load even without the tensioner. I have over 300 miles on my Huffy Cranebrook from Wally World with the same type tensioner, but the rear section of the bike is STATIC and doesn't move. This movement also might move the sprocket laterally! I would try to stiffen the rear frame where the shock is, install a heavier duty chain (the stock ones SUCK!)and try running the bike without a tensioner-Gearhead

 

[Pablo]

Who sold you this piece of garbage? Did they say they had actually started it and rode the thing? How much did he charge you?

Indeed - people need to include their location. I never understand why they don't......PLEASE INCLUDE YOUR LOCATION.

Don't ride it like that. Looks like a Shifter Kit and HD Front Mount will work and get rid of the whole left chain mess.

 

[rich2484richard]

gearhead you are right i dont how i missed that one. these engine kits do not work with rear suspension. you need to get rid of it, changes the tension on the chain and really buggers it up, you could really have a bad accident on it like that.

 

[RdKryton]

Please let us know who the Ebay seller is. He needs to be avoided. He is selling a product that will fail catastrophically and cause someone to get badly hurt or die! He also needs to be reported to Ebay. Does he have many listings or was it a once and done thing? This can not be taken lightly...

Jim

 

[gearhead222]

I wasn't going to say anything, but the other bikers are correct-this is a sloppy build. If it were me I would definitely report the seller and see about a return and refund, as he is selling a dangerous, nonworking product!