Fuel starvation problem has got me stumped.

I've got a 1996 200HP Johnson Carbureted. It's been having intermittent problems getting on plane. If I squeeze the primer it'll pick up and plane. Once it planes it will have trouble getting over 4000 RPM (surges).

I hooked up a feeder tank with a clean fuel supply to the primer bulb and it still has the same problem.

Cleaned all the carbs.

I hooked a vacuum gauge up to the fuel inlet side of the VRO it reads about 2 inches of vacuum around 2000 RPM when I accelerate it will go to 0 when the surging starts, sometimes it will creep back to 2 inches and the surging will stop.

The VRO is 1 year old and has maybe 50 hours on it. The fuel lines between the primer and the VRO are all pretty tight. I did notice when the air box was off that the gas that was puddled in throat of the carbs looked cloudy (like it could be getting aerated). I can't find any air leaks. I took the VRO off to inspect it, so far so good. I plan on picking up a vacuum pump tomorrow in order to test it. The only other thing I haven't looked at is that thing that's T'd on the fuel inlet side of the VRO, it has a 1/4 inch fuel line going to it (not sure how to test it).

Any ideas would be greatly appreciated.

Thanks
Vic

HHMM a couple of things seem a bit funny, first off, pumping the fuel primer bulb in effect bypasses the fuel pump, so that could be a clue, also you said you connected a new tank to the primer, but that still leaves the primer as a suspect (though unlikely) and the rest of the fuel line, also make sure you did the carbies properly, cloudy fuel "puddled" could mean it is mixed with water, not aerated.

I'm going to a pick up a new primer tomorrow even though the one I have is one year old. Compression is between 100 and 115.

Does anyone know how to test the pulse coming from the crankcase? Wondering if it's not strong enough.

You did open the vent on the tank right?

you seem to be stuck on the pulse and vacuum readings and so on, don't look for the really hard stuff first, do the easy non invasive, no cost stuff first, you are getting way ahead without knowing the very basics of trouble shooting. It could be as simple as Bassmeister just said

I got a 96 200 venom. it had simlar problems after i rebuilt the fuel pump. the pin under the diaphram has a o ring that is very tight. once i got it worked out ihad a problem with a dead spot at high rpms. I took it to my mechcanic, which I would trust with my wife & my money. As he was working on it while ideling it for an extened time it would die. He replaced the bulb & it did the same thing. he looked at me & said you got a pump problems. And at high rpms, same thing. He has got the same motor he raced for years & has worked on this one from day one. I believe him. It still dies on occation when idiling around sometimes & still got the dead spot. The pump is only 300.00+ dollars!!!!!! when I save up enough money i'll fix it then. hope this helps??!! http://www.bassboatcentral.com/smileys/eyes.gif