[Firebranch]

I bought 2 Chinese 49cc scooters a few weeks ago for me and my wife to cruise on. One of them runs good after a new carburetor. The other one Is acting really weird. So when it is cold it starts right up (usually) and after if heats up if I kill it, it will not start back up (even if I use ether). I've replaced the carburetor twice, new spark plug, new rectifier, all new fuel and vacuum lines and new fuel filter. At this point I have EVERY line except for the vacuum and fuel line taken off. The little black electric box next to the battery is also new. I also have the stock air filter taken off and have a new direct to carburetor intake filter installed. I'm not completely stupid with motors, I know that for a motor to run it needs, fuel, spark and air.. at this point it's getting all of those and still doing the same damn thing. ANY help would be greatly appreciated.... I you like me to send pics of ANYTHING just let me know.

 

[Firebranch]

Here are some pics of the carb and lines...

 

[Firebranch]

I'm so ready to get this issue fixed... I'm ready to cruise down the road at a smooth 35mph....

 

[Steve Neul]

It might help if you would post the year and make of the scooter. I don't work on bikes. If it was an older car I would be looking at the timing.

 

[RogerC60]

I know that for a motor to run it needs, fuel, spark and air.. at this point it's getting all of those and still doing the same damn thing.

It also needs compression. Maybe a valve is operating properly when the engine is cold, but starts acting up when the engine is hot?

 

[ExTex]

If it won't start with starting fluid, I'd check the spark.... probably the coil if heat kills the spark.

It sounds like another new bike would be cheaper than all the parts you bought ??

 

[Rogue1]

If it won't start with starting fluid, I'd check the spark.... probably the coil if heat kills the spark.

It sounds like another new bike would be cheaper than all the parts you bought ??

I concur with this

 

[Firebranch]

Thank you ALL for the help.. I ordered a new coil and will let you all know Sunday after it comes in if that fixes it.. If this doesn't then I'm throwing the damn thing in the burn pit....

 

[Firebranch]

I'm also about 90% sure the Stator is bad.. The lights are SUPER dim (I checked all the wiring everything is good) (Including new bulbs), When I rev the motor they get a bit brighter. So I also ordered a new Stator and hopefully between that and the coil I should have a good running scooter...

 

[SemiFast]

I ordered a new coil

I also ordered a new Stator

What is the condition of

S F

 

[Zip143]

Some of these parts you're throwing at it can be tested. You can check the coil, stator and R/R with a multi meter. There are many tutorials on youtube, very easy to do and you don't have to have a high dollar meter to do it. I'm not clear on how long you are running the bike before shutting it down but if you are not riding it and just killing it after letting it sit and idle for a bit then one thing extra to check would be the electric choke. It's that black part sticking up out of the left side of the carb. It's actually an enrichener that allows extra fuel in at start up. It gets power from the stator directly I believe (3 phase ones do, I think you have a single phase so not sure but it gets power from somewhere). Follow the wires leading from it. When the bike is cold, its always open. When you start the bike it gets powered up, heated and closes and stays closed until the bike cools down after a ride. If for whatever reason its not getting power and closing, your bike will start when cold but not restart when warm because it's way to rich now with the choke/enrichener opened. Just something else to check.

 

[Norton John]

If it won't start with starting fluid, I'd check the spark.... probably the coil if heat kills the spark.

It sounds like another new bike would be cheaper than all the parts you bought ??

Watch out using starting fluid (either) it can and will blow a hole in a piston if you use too much.
I agree, check the timing first. I expect that it is a 2 stroke?

 

[hogcowboy]

Watch out using starting fluid (either) it can and will blow a hole in a piston if you use too much.

I agree. If you must use something use carb cleaner. If the bike is going to start it will start with this. Leave starting fluid to diesels as intended.

 

[bweighmaster]

Starting fluid is just for checking ... Are we talking 2 stroke , or 4 stroke engine ?
Brand , year , model would also help .....