I believe I have a 2000 or 2001 sierra 90. Hasn't ran in a few years. I Drained fuel, changed plug, cleaned the carb and she fired up. I rode it around the yard a few times and the carb tube kept popping out of the air box and it stalled out. Then it wouldn't start so I cleaned carb again. No luck. Changed plug again and no luck. Thought maybe the electric choke so I bought a new carb. Still no luck
Compression is around 105lbs a little low but should still run. Good spark, I can sometimes get it to fire but it acts like it's running out of fuel. I disconnected the fuel lines at petcock and "On" barely trickles "Reserve" flows but not strong so I bypassed the petcock and it still acts like it's running out of fuel and won't take throttle at all when i get it to run. Also gas cap tube is clear 9f debris. So is there no other vacuum lines? Not sure why it's not filling up with fuel quicker

 

If it is a 2 stroke, check the exhaust isn't blocked. After a long lay up, either bits of carbon or rusted baffles can drop off and block the passages in the exhaust. If the fuel tap wasn't screwed into the tank, there may be a filter on the tank outlet. Check if it has, and clean it.

 

I checked the exhaust already. Tank only has external fuel filters and they were removed. I replaced the fuel line from petcock to carb w8th a clear line So i can see the fuel getting to the carb but it won't fire or when it does fire, it won't take throttle. When I check the plug after trying to start it, the plug is wet and basically fouled. Maybe getting too much gas at crank? It definitely isn't getting enough fuel when I get it to start. It will idle for a minute then die, that's why I was wondering about vacuum. I can see the fuel in the line going into carb but it still dies like its out of fuel...I'm stumped

 

Not sure if the float level is adjustable on that engine, but I had an LT50 Suzuki which did that trick and it turned out to be the float. It was allowing fuel in very slowly. However, you have swapped carbs, so shouldn't have two carbs with the same problem. Sometimes faults that seem like fuel, are ignition, but there won't be much you can do about checking that, other than substitution.

 

I am also having some issues with my eton DXL90. My problem was when I gave it throttle it bogged down. So I got a new carb on it and now it won’t even start going we have gone through the old starter and I am looking to get another one on it. Any suggestions as to what to do about this. I have a Chinese Atv as well it has been running well since I bought it until today. As I was riding it, it all of a sudden seemed like it had run out of gas. Went to check the tank and it was still half full. It still starts and everything, but when I put throttle on that it goes and then stops and then I let off and it goes and stops. I’m sorry that’s a bad explanation but I don’t know what is up with it.

 

With the ETon check if you are getting power to the starter motor by putting a 12v test lamp between starter live and earth, press start button, if lamp lights brightly, faulty starter, if it doesn't but solenoid clicks, faulty solenoid or loose thick wire (including earths). If solenoid doesn't click, faulty wiring to solenoid or could still be faulty solenoid, start checking thin wires to solenoid.

Regarding Chinese quad, fit a new plug, could just be that, if not, could be a partly blocked carb. Remove float bowl, remove jets, blow bowl, jets and the holes they came from out with compressed air. Re-assemble and see if that has fixed it.