Husqvarna 450 not starting after top end rebuild

[gable logan]

I have had this husqvarna for 12 years, served me very well up until last summer. Piston was scored aswell as the cylinder, put new piston and cylinder in and will fire 2-3 times but not actually run. I have a new carb in there and everythings hooked up correctly.. Lines aren't cracked either.

 

[J D]

Aftermarket parts?
Purge bulb definitely hooked up the right way?
Did you identify the cause of the original meltdown?
Vac & pressure tested?

 

[gable logan]

Aftermarket parts?
Purge bulb definitely hooked up the right way?
Did you identify the cause of the original meltdown?
Vac & pressure tested?

Aftermarket piston and cylinder, OEM carb
Yes, small nipple on primer bulb is attached to the line going to left side of carb, then the large nipple on the return line.
Nope
Haven't done one yet but I'll do it tommorow.

 

[J D]

Aftermarket stuff is pretty hit & miss.
I'd measure squish &/or compression if you can.
I can never remember which barb is which on those bulbs... it should suck fuel up through the carb & blow it back into the tank.
What have you got the carb L & H set at?
Does it fire again if you re-prime it or put a few drops of fuel down the carb? If so check you haven't got an obstructed impulse passage somewhere.
Vac/pressure test is highly recommended if you want to avoid your new piston & cylinder going the same way as your old one in short order.
I'd hold on to your OEM cylinder, it may clean up & it will be of far better quality than your aftermarket one