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.
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?