Help please

[Dang]

So i have a 2003 blaster, and decided to rebuild it, because i cracked the crank case. so we split the case, resealed it, then i got a new ported cylinder, new piston, new reeds, new carb, new head, and new spark plugs and it won’t start on its own. it will only start if you put gas directly into the cylinder through the spark plug screw. and while it’s running it isn’t running well, there is exhaust coming out of the carb, and will die if you don’t have a little on the throttle. i am unsure what to do, i have compression, and spark. please help

 

[Slydog]

If you had flywheel off ?check keyway.
Also check those reeds again. They have to seal tight on tips. No cracks or chips?
What carb cam with this kit? Chinese junk?
Try your old cab.

 

[Dang]

If you had flywheel off ?check keyway.
Also check those reeds again. They have to seal tight on tips. No cracks or chips?
What carb cam with this kit? Chinese junk?
Try your old cab.

thank you for your response, why would the fly wheel affect the gas going into the cylinder? and the reeds are brand new carbon fiber reeds, i do not see any cracks or chips in them

 

[Awk08]

What jetting is in the new carb ?
float height ?
airscrew setting ?

we've never found any aftermarket carb that has the slide #, needle/jet or any of the jets that are correct for our blasters, None, whether listed for a blaster or not. the stock carb with stock internals and jetting is your best bet.
(main jet adjusted for any intake or pipe mods using plug chops to determine that)

and stop dumping fuel down the plug whole, or using starter fluid, your washing the oil off your brand new cylinder/piston/rings

as mentioned above, if the flywheel key is sheared or missing, the flywheel will rotate out of timing and fire at the wrong time, it could be firing the plug while the reeds are open and blowing combustion back thru the carb

 

[Larry's Shee]

Are you trying to run it without the air filter? Is what you see look like a fog in front of the carb, or is it a single shot of blue smoke shooting out?

 

[Daryl Schmitz]

Did you do a leak down test after the rebuild? If not I would start there