Hey now I have a 8 yrs old yt 4000. never had anything but non ethanal gas put into it. I have taken the carb off and it is clean as a whistle. But for some reason the only way I can get it to start is to spray starting fluid into it. I have changed the plug and cleaned air filter. Anybody help with this?
Here's a couple of things to check. If it has a fuel pump, check the small rubber tube that goes from the fuel pump into the valve cover. They have a tendency to crack. Even a small crack could keep the pump from sucking fuel because it's sucking air through the crack.
If that hose isn't cracked, remove the fuel line that goes from the fuel pump to the carb, and then turn the engine over. Fuel should spit out of the fuel pump. If it doesn't, I'd check the fuel lines, it could be blocked or collapsed. Remove the fuel line that goes from the gas tank to the the fuel pump, and see if any drains out (into an empty coffee can or something else)
If that doesn't work, I'd say you have a bad fuel pump. Because gas is going into it, but not coming out. And with the rubber tube (to the valve cover) not leaking, then the ONLY thing left, that I can think of, is a bad fuel pump.
