My JS400 was running fine until one day I loaded it up in my truck. Once loaded it wouldn’t start, so I got it offloaded, trying to get it started I blew out the starter clutch. I knew I wrecked the starter clutch when the starter would spin but the motor would not turn over. I changed out the starter clutch and also put in a new starter as well, put it back together and now the quad will not start. It won’t even fire, pop, gurgle, or anything. I put a new spark plug and checked for a spark, I get a nice blue spark. I tore apart the carb and cleaned it out, it had a little bit of gunk in it but I have seen worse. I pulled the valve covers off and checked the valve clearance and they were bang on for spec. I’m really frustrated and confused, I’m making spark, I’m getting fuel and have compression, should I not at least get some life out of this beast???

 

Did you drain the float bowl to see how much fuel is in there?
Did you remove the air filter and cover the air intake to act like a choke?

 

did you ever figured out what your issue was? I have the same exact thing going on right now and I’m stumped.