Fuel starved?

[BWL]

Fellas, I don't think I'm getting a strong enough pulse to power the fuel pump. I'm running the pulse fitting off the manifold after the carburetor. Since this is a marine application, I have a bulb on a true marine gas tank. Once I prime the carburetor bowl full of fuel, it will run for about a minute or so the die. I'm guessing no gas is being pumped. I'm running a NR 230 cam, so I figure that wouldn't be too much camshaft, but I still don't think I'm getting a strong signal.

Do you get a stronger signal off the valve cover?

 

[OND]

Sounds like you are running out of fuel... I would pulse it off the valve cover with a fitting or on the intake behind the carb. JMO

 

[DeadPixel]

Maybe your check valve in your bulb is restricting your flow. If you are running a cam I am going to guess you have a billet rod and aftermarket flywheel and have removed the governor and low oil switch. If so maybe try hooking to the top of the block. I would first try priming your carb and then take the bulb off your fuel line and hook up your fuel with out it. Most pumps are designed to push not pull. The check valve might be too much for the pump to pull against if the primer is installed between the pump and tank.

 

[BWL]

Thanks, guys. I'm running a Box Stock motor with an ARC rod and flywheel. I shortened the fuel line coming off the gas tank. I found an old ARC Race Ready carburetor and bolted that on. I also reset the valve lash. It seems to be running now.

Seems like I've heard about the check valve before. Also these modern marine tanks are not vented, so I loosened the cap a little, and it seems to be flowing better. But you know everything runs perfectly at home, lol.

 

[DeadPixel]

Good to hear. I thought about the tank vent but forgot to mention it. I used a box stock for a parts doner on my build. Will definitely be getting one again next time I need a motor. Good quality. One thing i would recomend though is next time the head is off to lap your valves. My valves had not been lapped from the factory. Not sure if that is normal on these motors or not.

 

[BWL]

Wait, they don't lap the valves in?

 

[DeadPixel]

Mine were not lapped in. I took the head off to steal the exhaust valve on a new motor and valves looked new. No marks from being lapped. Just clean new looking valve. Next one I get I will check if the valves seal from the factory before I port the head. This might just be a normal thing on small motors. I will be pulling my head off my ct200u soon and will check how well the valves seal. That motor only has about 30 minutes on it and will have about an hour on it when I pull the head to install a flat top piston. If the valves leak I will post about it. Even on new heads for V8 motors it's normal for the valves to leak from factory unless it's a crate motor. It's sad but true.