630 LP will not start

[13wingnut]

630 Lp will not start. When I bought it they said it would only start if it was pulled. I have had it started off the starter but it was random when it would, now it is not getting gas. It has spark, I have eliminated everything up to the carburetor. When I crank it there is no suction on the low pressure line going into the carb. I believe it needs a signal to open the diaphragm in the vaporizer. I am looking for some suggestions before I pull what is left of my hair out

 

[MSD]

Is the air cleaner bowl on and full of oil? They will not start if that is missing or empty. Behind the regulator there is a small hole. You can put like a straw from a spray can or something similar in the hole and gently push it in. You should hear gurgling or hissing sound if it is getting gas.

 

[13wingnut]

Is the air cleaner bowl on and full of oil? They will not start if that is missing or empty. Behind the regulator there is a small hole. You can put like a straw from a spray can or something similar in the hole and gently push it in. You should hear gurgling or hissing sound if it is getting gas.

The air cleaner is full. It has been converted to an impco jb-2 vaporizer before I got it. There isn't a prime button on it.

 

[NY 986]

630 Lp will not start. When I bought it they said it would only start if it was pulled. I have had it started off the starter but it was random when it would, now it is not getting gas. It has spark, I have eliminated everything up to the carburetor. When I crank it there is no suction on the low pressure line going into the carb. I believe it needs a signal to open the diaphragm in the vaporizer. I am looking for some suggestions before I pull what is left of my hair out

On a gasoline burning tractor what you describe with no suction might imply a bad manifold gasket or manifold itself.

 

[Tx Jim]

Is fuel control solenoid receiving 12 volts when ign switch is turned to on position? I suggest to change fuel filter item 12 part # AF1399R if it hasn't been changed lately.

 

[13wingnut]

Is fuel control solenoid receiving 12 volts when ign switch is turned to on position? I suggest to change fuel filter item 12 part # AF1399R if it hasn't been changed lately.

All of that has been bypassed

 

[13wingnut]

On a gasoline burning tractor what you describe with no suction might imply a bad manifold gasket or manifold itself.

There is suction on the intake of the carb but not a vacuum signal to the low pressure lp input to the carb

 

[NY 986]

There is suction on the intake of the carb but not a vacuum signal to the low pressure lp input to the carb

But is the suction sufficient? All engines using a carb carried a spec for sufficient vacuum that in turn required a vacuum gauge to test for. A test port was normally located on the manifold. Be interesting to know where your tractor stands. Not starting via the starter but via a brisk tow start usually indicates insufficient vacuum. Since the automotive industry switched over to fuel injection during the 1980's I would imagine most mechanics do not have a vacuum gauge in their tool set.