80cc Engine kit - Almost Done , Running and Idling

[motortime]

I just like to share my motorized bike with everyone. I am not a bicycle/motorcycle mechanic but I'm pretty sure this is fine. Thanks to Mr. Kiosk help, with his advise this motorcycle went possibly running. Thanks for the forum as well.

 

[Tyler6357]

Welcome...Your bike looks great! I have just a few observations:
(1) I would install rear breaks on that bike, if you are using a coaster break you might find that they don't last very long, the bearings are not designed to stop motorbikes, use a V break or Disc.
(2) Keep a close eye on those fenders, fenders have a tendency to vibrate loose and get thrown into the spokes!
(3) You will find that the fatter the tire the better your traction will be, what size tires are you using? They look kinda thin but it might just be the angle of the camera.

Ride safe

 

[motortime]

Thanks Tyler6357. I have tyres that are 1 3/8 in size. Yeah they are thin, I wonder what will be the allowance for the tyres that can fit my rim (the fattest tyres?). My rims are for 1 3/8 tyres, but is it possible to use a fatter tyres on it?

I also want to change breaks. .this one is just for test. I just want to check if my engine will work.

Thanks with the advice about the fender. I will also try to make it even more rigid, they are just actually for aesthetic. If they'll give me issues eventually, it would be better to remove them.

 

[Kioshk]

Looking good!

I second Tyler's observations...with two more:

Your chain looks tight; you may need to loosen it up a little bit. The slack-side of the chain should deflect up and down about 1/2-inch. You can adjust this tension by lowering the idler-pulley slightly.

Your frame looks great BUT I'm a little concerned that it doesn't have a top-tube. This makes it very susceptible to down-tube failure. You don't want your frame folding on you while you're doing 30MPH. Is suspect that your frame's steel and not aluminum. If so, you'll probably be OK: it'll start bending instead of snapping. Please consider getting a frame with a down-tube.

 

[motortime]

Mr Kiosk, I believe the slack side is the top side of the chain right? yes it is tight. ..Ill try to loosen it up in the spring side maybe. ..

I see, well Ill try to stay 20mph on this bike and a maybe 30mph on short period or just for a test, but not that long. .. since I will just use this for work.

 

[Tyler6357]

Kioshk is right about the chain, it should be looser. It's difficult to get the rear sprocket perfectly lined up with the engine sprocket and the looser it is the better it will turn if it's not perfect and the less chance it is that it will jump off the rear sprocket or get jammed in the engine sprocket. Check it as you break it in as chains will stretch some during use. Just adjust the chain idler-pulley to loosen it, just not too loose. Also, wider tires should fit on your rims, but it's ok for now, you will find that narrow tires will become bald quicker. When you need to replace them try ones between 1.95-2.5 wide and get the good ones with wire, especially for the rear one for best results. Go as wide as possible without the chain rubbing against the side of the tire. It looks like you have nice thick spokes on the rims, that is good! I personally recommend getting sprocket adapter and not putting the drive force on the spokes but others might disagree with me. Make sure you check all the screws often. Screws have a tendency to become loose with vibration. After a while you will figure out which ones are problem screws that vibrate loose. Use blue lock-tite to stop screws from loosening where possible.

 

[motortime]

Tyler6357

yeah, I have encountered that chain loosen up while you use them. ..this is my third time adjusting my tensioner. ..before, it has 2 inches loosen space to go up and down and its weird that after I raised my rear sprocket with washers it is now tighten (with the tensioner on its same position). ..maybe you're right in breaking in the engine more before I make further adjustment with the chain/tensioner since it might loosen up again. ..

thanks with the tyre advice, I think i'll just wait until break in process is done. I'll note you're advice with that.

For the adapter, I am also eyeing on that.. .but that's quite out of my budget right now. But for sure that will be prioritized on the modification list with my bike.

Thanks for the Advice Mister!. ..

 

[Tyler6357]

Right on, ride it hard, break it in, just don't let it get too hot before stopping and letting it cool down again during break in. Ride it maybe 15 miles and then stop and let it cool down for 5-10 mins and then go again. keep checking screw tightness. Carry some basic tools with you if you get stuck on the side of the road, they can often save you from having to peddle it home. Also, I can't see from your pictures but some of the cheap kits come with really horrible spark plug boots, it is highly recommended that you get a high quality automotive quality spark plug boot at the autoparts store, they are only about $5. If you had to take off the spark plug cap to get it to work you probably have a terrible plastic one, get the rubber kind. Not all kits have this. Where did you buy?

 

[motortime]

Thanks!. ..I'll note that break in process with the tools. Its hard that your engine chain got stuck without tools for your to pedal the bike.

I have a rubber spark plug boot. ..it is stock, but I'm fine with it. I don't know if it last. ..I have rode my engine maybe 50 miles? It's so short that I just test my engine if its working and can Idle and that would be too short as well to test the quality of the cheap parts. ..I'll try to change the spark plug boot cap if possible and the spark plug itself.

I bought my engine kit on ebay. They said it is the upgraded one (as of 2015). ..but I am not sure with that.