Anyone know anything about dirtbikes?

[Wolfie]

Before I get a hammering on here about how I shouldn't have bought a Chinese knockoff, I didn't want to pay a lot of money for the bike. It was for my kid and I didn't want to pay an arm and leg for the kid to say he didn't like it.
This weekend I found a bike. It's a 2004 Flywing MX100. Made by Jianshe so far as I can tell.

The kid started ridding the bike and as getting the hang of it, but when he went to downshift after about an hour or ridding, the rear wheel locked up and now the bike will not start or turn over for that matter. Did something happen inside the tranny that I should be worried about? And if so, could it be stuck between gears or something and be an easy fix?

If not, where can I find parts for this thing? I have been on the internet looking for dealers and that sort of thing everywhere but I can't seem to find anything.

Any help would be greatfull. Thanks again.

 

[SpeedEng66]

2t or 4t?

 

[milesl]

Pull the clutch in and try to turn over the motor.If the motor cannot be turned over and the bike can be pushed freely,then the motor has locked up and it needs engine work.This happened on a dirt bike I had.The piston skirts broke off and seized the motor.
If pulling the clutch in makes no difference,then it may be a transmission or clutch problem.
If when trying to Start the bike it wants to move forward on you, the clutch may have locked up.
If the clutch feels really loose the cable may have broken.
Good luck.

 

[Killrose]

Pull spark plug look down into cyl with flashlight and see if piston moves at all while rocking the machine back and forth. If this unit is a 4-stroke, remove oil and inspect for metal particles or chunks.

 

[Wolfie]

Sorry guys. I should have mentioned all this before.

It's a 4 speed auto. What this means is that it doesn't have a clutch. You just try to find nutral when you start it and upshift from there.

The motor and transmission on this bike is all one unit. It's a 4 stroke. The crank uses the same casing as the transmission. There is a gear the goes from the crank, straight to the imput shaft on the transmission. Then it basicly goes to a secondary shaft for the output and where the chain goes to the wheel.

I took the thing appart and found broken gear sprokets. Hence the reason why it was locked up. Now I either need to find a place where I can find parts for this thing, or junk it. I guess for the price, I didn't go too wrong with it. Now I just need to find a new bike. 🙂
But if anyone knows a place where I can find parts for this thing, it would be nice.

 

[SpeedEng66]

do you know what kinda chain it uses? 420?

I might have a sprocket

 

[Killrose]

Look on ebay. Probably some of the parts you need there or they will soon show up no doubt.

 

[Wolfie]

Killrose,
Believe it or not, there was only one bike that was on Ebay that even came close to what I had. Nothing else. No parts no nothing. hehe The disadvatages of having a chineese knock off bike. (not trying to say that everything chineese is bad. Just hard to find parts)

Speedeng,
It's not the sprocket that is bad. The gears inside of the tranny are bad. Broken teeth. Thanks anyways.

 

[jagec]

Originally posted by: Wolfie
Sorry guys. I should have mentioned all this before.

It's a 4 speed auto. What this means is that it doesn't have a clutch. You just try to find nutral when you start it and upshift from there.

The motor and transmission on this bike is all one unit. It's a 4 stroke. The crank uses the same casing as the transmission. There is a gear the goes from the crank, straight to the imput shaft on the transmission. Then it basicly goes to a secondary shaft for the output and where the chain goes to the wheel.

I took the thing appart and found broken gear sprokets. Hence the reason why it was locked up. Now I either need to find a place where I can find parts for this thing, or junk it. I guess for the price, I didn't go too wrong with it. Now I just need to find a new bike. 🙂
But if anyone knows a place where I can find parts for this thing, it would be nice.

Got access to a machine shop? You might be able to fabricate something, *or* if you're really lucky you could shoehorn in a similar transmission from a different bike. One guy online says it might be based on a Honda Trail 70-90...maybe that would fit?

At that point it might be more work than it's worth, though (in fact, I'd argue that machining a replacement would also be more work than it's worth). Try checking Craigslist/ebay for a used Honda/Suzuki/Yamaha/Kawasaki? Can't be too expensive...