Power loss at 3000 RPM

kschnebly

Seaman
Joined
May 15, 2013
Messages
64
I have a 1991 3.0 LX with alpha one drive. WE were out a few weekends ago and boat was running well. at the end of the outing the starter crapped out. changed it out along with plugs. boat now stumbles over 3000 rpms. Plugs are sooty. runs fine not under load. HAS rebuilt carb, new cap, new wires. photo.jpgphoto1.jpg
 

alldodge

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Mar 8, 2009
Messages
40,583
Re: Power loss at 3000 RPM

With the plugs being sooty it sounds like your flooding the engine. Pull the top off the carb and see if you have some crud it there. Has the fuel filter been replaced? Is there old gas in the tank and was it winterized?
 

kschnebly

Seaman
Joined
May 15, 2013
Messages
64
Re: Power loss at 3000 RPM

The boat was left outside last winter by the previous owner. This left it in pretty rough shape. The tank has all new gas and there is a new fuel filter. The carb was a mess. I really probably should have gotten a rebuilt one instead of rebuilding it myself. It took me five times to get it to where it was running well. It just so happens that on the trip that the boat started to run well the starter went out. In order to change the starter I disconnected the plug wires, removed the fuel pump, and decided to put another set of plugs in while I was at it. Boat fired right up but if you dropped the throttle from half to neutral quicly it would die. A little adjustment on the idle and idle fuel mixture screw and it ran great. Took it to the lake the following weekend and couldnt get it to plane. I was eventually able to get it to go up on plane but only by feathering the throttle. Once on plain when the engine got over 3000 rpms it starting loosing power and would drop off of plane . Couldn't get boat over 20mph. Checked the distributor cap and it was fine. Checked all I know. The boat revs right up on muffs in and out of gear. No missing or hesitation. Once in the water it idles fine and with light throttle runs good. Once you give it more throttle. I guess I am back to the carb.
 

alldodge

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Mar 8, 2009
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40,583
Re: Power loss at 3000 RPM

Still sounds like a fuel issue. Rebuilding the carb your self is fine so long you have the means to get the carb cleaned out and adjusted properly. May want to go and pickup another carb.
 

kschnebly

Seaman
Joined
May 15, 2013
Messages
64
Re: Power loss at 3000 RPM

Spent the morning pulling the carb and going back through it. Everything on first inspection looked good. Figured I would break it down again since it was off the motor. Put the screwdriver on the accelerator pump and noticed it was loose. Took about two turns to remove it. Put it back in and it took about five to get it seated. My guess is I never tightened it and it was vibrating loose. At 1/2 to full throttle it was pulling fuel around the jet instead of through it. i.e. the flooding issue. Put it back together and heading to the lake later today to test it out.
 
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