First Project

[falcon1]

My first project will be a rebuild of a minibike I won at a fair. It is a racing bike (sort of) and worked fairly well untill recently. It looks like the one pictured except mine is green and black. It has a small two stroke engine capable of bringing it up to speeds of 28 mph (in theory, though I've never been that fast in it). The acc takes forever to really kick in, sort of like turbo lag on a car. Only thing is, in a car the turbo isn't needed for the car to move faster than a jog. When you turn the handle to full power, it slowly starts off moving at a little faster than walking pace for about 10 seconds. It then hit a speed of a light jog. A few seconds later, you hear the engine really rev, and it jumps forward like it has been stung, accelerating at an enormous rate. Unfortunatly I have never experienced the full acceleration as by then I have run out of road. However recently, I can't even start it. I have taken the plastic sides off and have it upside down over a bucket so that the fuel can drain. I suspect the carburator, but if anyone knows something about this type of bike that it could be, let me know. I plan to take care of the acc lag by removing the governer (also let me know if you think that will improve things). Any suggestions, comments, etc are welcome.

 

[Pellethuntr]

Doesn't sound like you have any lag to me, sounds like a clutch problem.. I wouldn' take the governor off of a 2 stroke because it is already running at plenty of rpm's.. but that's just my opinion

 

[falcon1]

What sort of clutch problem?

 

[falcon1]

Also the engine is reletively tiny and the bike is only about 3' long and 1' and a bit high. I weigh 180 lbs so I think it is weight combined with the fact it is on a slight uphill angle.

 

[Pellethuntr]

What sort of clutch problem?

Honestly idk.. I have never had one of these engines, but if it starts off slow and then all of a sudden takes off at top speed then that would be a clutch issue.. It sounds like it is not engaging correctly.. Is it a 4 speed? It could be that the clutch cable is adjusted wrong and does not fully engage went let out, or that there is some sort of internal problem.. If it is just a "one speed" so to speek and you don't have to shift, then there may be something holding the clutch springs from engaging.. When you say "acc" would that be automatic clutch control? Removing the governer would not fix any of your problems imo

 

[falcon1]

acc= acceleration. The clutch is pretty much part of the engine so I would prefer not to take it off. It also doesn't look in bad shape. Someone told me that with that type of engine it will go at that slow speed, then something else (can't remember what as it was years ago) kicks in and you really start going.

 

[falcon1]

Also, I just watched a race with this sort of bike, and the racers had to have a running start to get going, presumably because of acceleration problems. This bike has one gear at the back, so you can compare it to riding a bike from a standstill at 7th+ gear. The bike did that from the start even when everything else was fine.

 

[falcon1]

Minibike is now dismantled. I am taking the carb off and going to clean it.

 

[numscul]

I have had lots of fun working on mini pocket bikes in the past the one i remember the most is the one i called my little green monster ...i turned my 49cc engine in to a 53cc stroker motor and i can tell you it was a beast of a bike for its size ...i ended up selling it to a 300lb fat a$$ that broke it as soon as he got it home
Just wondering is it a reed motor ??

 

[falcon1]

Nice sounds fun The motor is a two stroke gas motor. I am cleanin the carb today, or at least removing it.

 

[falcon1]

The carburator was clogged. I used an air pump to clear it out. It has been put back in and I am putting the bike back together. I may post pics when done.

 

[falcon1]

The bike is mostly back together. Just need to put one final bolt to hold the brake on and make sure the rear wheel is straight. Also need to bolt on the rest of the bodywork. I think I'll put pics on when I am finished.

 

[falcon1]

Bike re assembled. Still won't start. I am going to check the kill switch this weekend

 

[j.concepcion54321]

I think those bikes have pretty decent get up and go when they're running right. I had a 49cc and it ran terribly then I cleaned the carb nice and adjusted the idle screws and made sure to use the proper gas oil mix. Check the spark plug if its not runniing. I'm 130 and that bike had me flying right past my go kart at top speed.

 

[Sentrek]

Use the idle adjustment screw to set the idle high then try to start it, when it starts and runs for a few minutes readjust the idle. You should be able to adjust it with your fingers. In order to set the idle higher twist the throttle and turn the screw in, it should turn easier that way. A shot of ether simplifies getting it started as well.

 

[falcon1]

Where can I locate the idle adjust screw? What does it look like? Spark plug is not the problem. Neither is the kill switch