Zenoah G320 won't pull fuel.

[Rain13a]

New to the hobby, third run with my Vekta 5 and the Zenoah G320 stalled and died. The fuel bell was completely empty but the tank was full. When I try and prime the engine it won't pull fuel but it is pressuring the tank (if I pull the fuel line off fuel will flow freely). I pulled the carb and inspected all the seals look good. Any ideas on what to check next? Thanks.

 

[Rep732]

We need to see pics of your carb and the insulator, the portion that holds the carb to the engine. It sounds like your engine is vapor locking if you have no fuel in the primer bulb. The other possibility is you have an air leak issue with the primer bulb or gaskets holding the top portion of the carb on.

 

[Rain13a]

We need to see pics of your carb and the insulator, the portion that holds the carb to the engine. It sounds like your engine is vapor locking if you have no fuel in the primer bulb. The other possibility is you have an air leak issue with the primer bulb or gaskets holding the top portion of the carb on.

Hope the pics help. I've completely taken the carb apart so not sure it would be vapor lock.

 

[Rep732]

Ah gotcha now in your original post. Sounds like your tank is causing the lock. Have you made sure when you assembled the vent in the cap its facing the right direction? It's to allow air in but not vent out. Try to draw fuel into the bulb with the cap off.

 

[Rain13a]

Ah gotcha now in your original post. Sounds like your tank is causing the lock. Have you made sure when you assembled the vent in the cap its facing the right direction? It's to allow air in but not vent out. Try to draw fuel into the bulb with the cap off.

With the cap off I can see the bubbles from the fuel line going into the tank but nothing coming outta the tank. I've removed the fuel filter to eliminate that possible fault.

 

[Rep732]

That's interesting, so let's diagnose this and hopefully it's easy.


The yellow line that comes to the top of the carb that's the return to the tank that carries the bubbles, is there fuel going through it or just bubbles? The black line to the bottom of the carb is the fuel supply. My next question is did you buy this engine complete or did you assemble it yourself? It sounds like your losing prime at the carb and we can continue further if you mention all I asked is ok.

 

[Rain13a]

That's interesting, so let's diagnose this and hopefully it's easy.


The yellow line that comes to the top of the carb that's the return to the tank that carries the bubbles, is there fuel going through it or just bubbles? The black line to the bottom of the carb is the fuel supply. My next question is did you buy this engine complete or did you assemble it yourself? It sounds like your losing prime at the carb and we can continue further if you mention all I asked is ok.

Ok, you talking through the fuel path enlightened me and I feel like an idiot. I'll admit it, crossed the lines. I thought the line nearest the bulb was intake. All's good now. I'm gonna have a drink. Thanks for your help.

 

[Rep732]

I'm glad you have your issue under control. I hope it's a good drink as you deserve it, and enjoy your rig!