Yamaha Moto 4 No start need help

[Elijah Stone]

Hi all new to the forum I have a Yamaha Moto 4 champ (100cc?) (YFM100) so I've been trying to get this thing to start for awhile honestly I'm running out of ideas so I'll start with the things Ive replaced and done first it was not trying at all and then I put a brand new battery then the terminals broke so I bought some nice copper ones fixed that up so now battery is got good voltage and all that I have checked all the plugs cleaned everything off so anyway it still wasn't trying but I couldn't get the crank case off and I didn't think using fire was a good idea lol so I busted the crank case off on the left side(if you are sitting on it) wierdly enough the flywheel started spinning I thought it was odd but went with it then I replaced the spark plug still wasn't getting spark so I replaced the ignition coil then it was getting spark next the carburetor was really gross I cleaned it out still wasn't working so I in turn decided just to replace it with a new one so I did (PS I never figured out how the fuel lines hook up if someone wants to help with that to lol) also for good measure put a new air filter so then I pressing the button Everytime I replace something and nothing so then I think what if it's the stator so I have no idea what a good or bad stator looks like but me being to rough I broke the wires on the thing but still no changes the fly wheel spins gets compression (I think) getting spark from spark plug idk other tidbits that might be useful I don't have a clutch line so idk if that has something to do with it I do have the break zip tied in to bypass the safety feature also the throttle cable is in fact broken and I'm working on buying a new petcock for my gas tank because my current one is broke I have very limited money this is supposed to be a project before I go to school for welding and automotive tech so I don't have any money to get a mechanic lol but I'm pretty confident in my ability to do anything u suggest any suggestions are welcome I'll edit and submit pics

[Frank Angerano]

Welcome to Quadcrazy @Elijah Stone  Thats some write up.

Once you replaced the ignition coil and you had spark the stator should be left alone since the spark is there.

The fuel lines are not difficult to put on, there should only be one fuel line on the left side of the carburetor and the others would be a vent hose that may run up behind the gas tank and another hose would be connected to the bottom of the bowl on the carburetor and do noting but hang down under the frame. It’s called an overflow hose  that allows fuel to spill out of in the event the carburetor had a failure of some sort or the bike is flipped over.  Both hoses would be generally smaller then the fuel hose. 

So what I would do is for now turn the gas off. Pull the spark plug out and test for spark.  Take the spark plug and plug it back into the ignition coil wire and rest the metal part of the spark plug on he engine head. Make sure your kill switch is on and crank the motor. You should see a spark at the plug right at the gap. Make sure it’s plugged in good and touching the metal part of the engine. 

 

If you have spark that’s great, put the spark plug back in and then make sure your fuel lines are properly connected and discussed. If your not sure then post some pics and we will help you along. If you figured it out then turn on the fuel and crank the engine. The bike should fire up just make sure your choke is working properly. 

Unfortunately these things cost money to fix so your going to have to spend a little money if you want to get it back to good.  

Let us know how it goes.  

Good luck  at welding and automotive tech  school. Your going to enjoy it, stay focused and learn as much as you can! 

This will be a fun little project to work on for you as well as learning a lot about the atv world just be careful. 

👍🏻

 

 

 

 

[Elijah Stone]

@Frank AngeranoThank you so much for the reply I do in fact have spark I'm not home rn but when I do get home I will post pics of the fuel lines I just replaced my petcock valve on the gas tank because it was corroded and green and had none of the little things that go into the gas tank I forgot to mention though that my headlight and neutral light will not come on the headlight used to work but now it doesn't so I did replace my Glass fuse holder coming off the postive terminal on the battery with a new one stupid me though didn't check the voltage to make sure the fuses where the same so I'm thinking that might be why my neutral and headlight arnt working but my starter does kick on so idk? Anyway when I get home I will post pics of the fuel lines