A4 Engine loses power

[jbuck]

Hi All,
I rebuilt the carburetor last year while I was on vacation. The rebuild worked for the balance of the year. After putting the boat in the water and starting it this spring, the engine started easily and idles fine. However, when I tried to increase the throttle the engine would "Fall flat" and I would need to pull the throttle back to keep the engine running. The next day the engine ran fine. I figured that everything was okay... then a couple of days ago the symptoms returned. The only way tto get additional RPM's from the engine is to pull the choke on.
I spent some time looking through the disscussion board and could not find any submissions with symptoms like this... if anyone could give me some ideas I would apprecate it. A friend of mine suggests replacing the fuel pump. It looks like the pump hasn't been touched in years. BTW, I installed electronic ignition a couple of years ago.

Take Care,
Jim

[Marian Claire]

Welcome to the forum. Sounds like the fuel/air mixture is changing as you throttle up. When you get up around 1300 rpm the main jet kicks in. If it has crude in it then the fuel would be limited and the choking/reducing the air flow would compensate. You could have a loose piece of crud that is shifting around. Or the fuel flow is fine and you have a air leak develop as you throttle up. This is less likely but it happened to me. http://www.moyermarine.com/forums/showthread.php?t=3369
Do you have the adjustable main jet? See pics here http://www.moyermarine.com/cgi-bin/s...rebuilder.html
Dan S/V Marian Claire

[hanleyclifford]

http://www.moyermarine.com/cgi-bin/s...=FPMP_07.1_473 Make sure you have one of these as close to the carb as possible.

[romantic comedy]

If it will run with the choke in, then you are not getting enough fuel. The mixture is lean. SO it seems that you should clean the carb. Get those jets flowing good.

You could also have an air leak in the carb.

[Dave Neptune]

Hoses?

Jim, does sound like something has entered the carb again. I'd try blowing it out again and then be sure to install a polishing filter between the carb and pump and I would als strongly suggest installing fresh hoses for the ones you tamper with when doing the R&R on the carb. I worked as a carb guy for quite a while and it was common for me find debris in someones "fresh rebuilds" and a great deal of the time it was bits of the hose from strggling to get them off the fittings. Often when pulling the hoses "off" the inside is comprimised and or cut. Those are the bits I found way to often!!!!

Dave Neptune

[jbuck]

Thanks all! - Fixed

I pulled of the carb and took it a part, replaced the fuel line and installed a new fuel filter. She runs like a new one... thanks to all that took the time to reply!
Take Care,
Jim