Problem with New Motor Idling

[Target9000]

Okay folks, input appreciated since I'm new to all this.

We just installed a new Beta 38 hp engine in our boat. Along with this all new tanks, hoses, valves, filters, etc etc. Filter setup is 30micron. The fuel tank is about 2 ft tall and about 2 ft above the engine with a pick up tube that goes almost to the bottom of the tank.

When we first attempted to start the motor I tried to prime the system with the hand lift pump. It never primed. Like it couldn't get enough suction to pull fuel through the whole system. Probably spent 30 minutes pumping.

To start it initially I rolled the engine over and it was able to prime itself (its a self bleeding/priming motor). It fired, ran a bit and died. I'm assuming it fired off the fuel left over in the fuel filter from the factory. After that I went ahead and tried the manual procedure with the hand lift pump again and found that it did pump fuel. So we did that, fired the motor and it ran fine for a while.

We now have about 25 hours on the motor. Each time I've needed to start the motor I've had to prime it. Usually I turn the motor over then use the manual lift pump because just pumping it doesn't seem to do anything initially.

Symptoms:
Once its running, if I let it idle for over a minute, it will sputter out. Anything above idle and it will run indefinitely. Runs great, sounds great, ran it for over 4 hours at a time no problems. If I have to go to low revs and shift back and forth a few times in a row, afterwards the motor will stumble but hasn't died.

I've read in the manual that the engine's lift pump is only rated for 8.25". However, the installer has done over 50 identical installs in boats like mine and has never heard of this problem.

1) I know it could be an air leak. How do I find it? I've tightened everything, all of it is new. Nothing looks even remotely loose.
2) Could it really just be asking too much lift of the pump? The manual says to install an electric lift pump. I don't have a problem doing that but why did the other W32s not have this problem?
3) Could it be an obstruction? How do I find it? I'm thinking of making up a vacuum gauge and putting it inline between every single fuel system junction in the run and measuring all the pressure at a constant RPM looking for a drop in pressure. Is this right?

The installer believes it may be an obstruction or air leak. Perhaps an off chance of a faulty engine lift pump. What would your systematic steps be to diagnosis this problem?

[Vyndance]

Did the installer do a turn key job or was it left to you to finish? The manufacturer says 8.25" and you are trying to go almost 3 times that much. But.. once it makes the lift pump it should be siphoning. I think I would try an electric pump at the tank.

[Target9000]

Originally Posted by Vyndance II

Did the installer do a turn key job or was it left to you to finish? The manufacturer says 8.25" and you are trying to go almost 3 times that much. But.. once it makes the lift pump it should be siphoning. I think I would try an electric pump at the tank.

Left for me to finish.

I was thinking that it should siphon after making the lift as well. The worry was that none of the other boats like mine have reported this to be an issue.

[Vyndance]

If you can get the specs for the lift pump you could put a gauge after the pump and see what you have. Is there a racor type separator or just the manufacturer's filter? Are the filters full after it has died or been shut down?

[Target9000]

Originally Posted by Vyndance II

If you can get the specs for the lift pump you could put a gauge after the pump and see what you have. Is there a racor type separator or just the manufacturer's filter? Are the filters full after it has died or been shut down?

The primary filters are 500 series style racors. They seem to be full after shut down. The filter on the motor is whatever came in it. I think its a 10 or 20 micron spin on type.

I can email Beta and see if they can give me specs on the lift pump.

[donradcliffe]

Since it runs well at higher rpm, its probably not an obstruction or lift pump issue. It sounds like an air leak, especially since the tanks and lines are newly installed. As a temporary fix, you could put an outboard motor squeeze bulb in the fuel line.

The Beta is not a self-priming motor--there is a valve which lets you bleed the system into the fuel return line without making a mess, but it needs to be closed for normal operation.

[Target9000]

Originally Posted by donradcliffe

Since it runs well at higher rpm, its probably not an obstruction or lift pump issue. It sounds like an air leak, especially since the tanks and lines are newly installed. As a temporary fix, you could put an outboard motor squeeze bulb in the fuel line.

The Beta is not a self-priming motor--there is a valve which lets you bleed the system into the fuel return line without making a mess, but it needs to be closed for normal operation.

Don,

I've suspected an air leak as well but as I asked, how does one go about systematically finding such a leak? I don't believe I've seen a straight answer on that. Do I just rip the whole thing apart and put it back together piece by piece? It seems very hard to find a problem like that.

Also, thanks for correcting me on the priming.

Thanks,
Tate

[Vyndance]

The electric pump or the bulb may show you a leak, fuel out air in. If you want a fool proof test from the tank to the injector pump through filters, lift pump and lines, plug at the tank and remove at the pump and draw a vacuum with a pump at the open end. If it holds vacuum no air leak.

[Chief Engineer]

Just a thought....if you instaled a racor did you coonect it up properly.

IN from Tank OUT to engine?