G2 will not run

[shifty8913]

I just picked up a project cart G2 gas, not running.
drained fuel tank and disconnected fuel pump and pumped out all old gas and some particles/dirt.
put in fresh gas.
Fuel pump pumps fuel to carburetor.
i installed a filter in the line to catch any additional debris that might go to carb.
Checked fire at spark plug and have a good spark.
motor turns over but seems to blow out through carburetor. I suspect a stuck valve maybe?
What should I do before I start taking things apart?

 

[djlan99]

The fuel filter screws into the bottom of the tank. You should change that ( when draining tank).

These engine have a very weak spark from the factory. You should be running a b4 ngk plug instead of the original b5 ngk.

Make sure the engine is grounded to the harness (engine frame is mounted in rubber).
To do this run a wire from the battery ground to the valve cover bolt.

This could be why engine backfires through the carb.

It wouldn`t hurt to pull the valve cover to check the pushrods and rockers. If a valve sticks open the pushrod will fall out (exhaust valve in your case).

You will not be able to save and reuse the gasket.

Also check for intake leak. These were known for cracked intake (plastic runner between carb and engine).

Some of these engines will run lean and backfire through the carb if the airbox is off or leaks air. They will still run but poorly or only with the choke pulled out. (so you don`t run the cart without an airfilter).

unplug and plug back in the ignition box ( dirty connection ). These do fail sometimes.

Check all of your wires to the engine. Check the wires going to the coil.