got a Fuxin 110cc quad. Engine was slightly seized, got it unstuck very easy and started to work on it to see if it would start up. I can get it to turn over,sounds really good, plenty of compression it seems but it will not fire. New jets, cleaned carb, used good parts from a running 110 but it just will not fire up. Took the spark plug out and it had pressure on it, more I loosened it, it hissed air.
Not sure I have ever had 1 do this so wondering what it might be a symptom of

 

If it was "slightly" seized it may "slightly" try to start. Best to do a compression check to see where you stand.

 

Push start it if you can.. my little 125 doesn't like to start in the cold, but if I push it, it will start. It's an auto btw. You can still push start it.

 

do you have spark? try a squirt bottle wit fuel and spray direct in carb. But like stated above check your compression first

 

yes has spark. and ive sprayed it with gas.

 

Do a compression test on it. Partial seizure could be from the piston/ rings or lower end bearings,etc.If compression shows around 100 psi or less you may just be wasting your time trying to crank it. If this is a 4 stroke Honda/Suzuki clone engine you might want to check valve clearance also if you just got this machine. At least it should have .002-.003 clearance on the intake and exhaust valve clearance.Tight valves can cause problem starting also.