04 Vmax carb 150 problem

The motor acts as if it is flooding out when I start to accelerate. It happens up until the RPMs hit 2800 or 3000, then it catches up and everything is fine. No problems running wide open or at 40-50 MPH on plane. But when I come off plane and get below 3000 RPM again it acts if flooding out again. Motor starts fine and idles well. This is happening consistently between this approx RPM range.
I have taken off the fuel filter on the engine and cleaned it and replaced the plugs. I run Stabil with every fill up and hit it with the Seafoam hard the last two fill ups. No change. Motor had been running fine until about the last 5 trips out. Bulb on fuel line will pump tight.

I have read a lot about similar problem and was looking for advice on the next step. Maybe a dealer to check it out, but I have read where changing the diaphram in fuel pumps or replacing the fuel pumps has corrected this. A friend had an engine cutting out at full throttle and he said he had to have the power pack replaced.

I'm no mechanic but replacing the fuel pumps look simple enough. Looks like parts can be found on boats.net.

Any advice would be appreciated.

Sounds like a carb is leaking. Have you pulled the spark plugs and look at them?

I pulled the plugs about a week ago. 4 of them were fairly wet and black. 2 were less wet and not nearly as dark. I hoped it was just a fouled plug issue, but the same problem exists after the last 2 trips out last weekend with the new plugs. I have not pulled the plugs again, sincelast trip though.

You might have a float sticking in one of the carbs. At low rpm this will cause flooding, but at high rpm more of this excess fuel is being burned. Rebuilding the carbs isn't difficult, if you have a proper set of tools and the mechanical aptitude.

I dropped it off at the dealer Friday. The tech said he would guess it is some trash collected in one or two of the lower carbs. He asked if I had been using the RED stabil and I had. He said the RED colored stabil is turning gelatenous with ethonal. He reommend ring free or the new marine formula stabil.

I have the same motor.............If you don't mind, keep us informed on what happens.........


Thanks,

Got the boat back week before last. 3 carbs cleaned up and both fuel pumps rebuilt with diaphram kits. It took care of the problem. I ran about 22 gallons through it in a tournament the next day. The dealer again recommended the new marine formula stabil, supposed to be made for ethanol blended fuels. Warned me again to not use the red stabil.

If you don't mind my asking, what did the dealer charge ya to get all this done? My old 150 proV could surely use this!