Spun Prop

[OldWilly]

Hello, my 1st post here. Will a spun prop cause the motor to act as if its starving for fuel ? motor is a 1985 Merc 60. It would not accelerate past idle under a load. I marked the prop and hub and the scribe marks were not lined up when I got back to the launch. I took the prop off and put the boat in the water and the motor will rev. Thanks

 

[Texasmark]

You found the smoking gun. Time for a new prop or a new hub. Your terminology is confusing however. Initially in using the words "would not accelerate" you imply that you were having an engine operational problem like starving for fuel for example. When you marked the prop you immediately shifted gears in the mind of the reader and put the concentration on the prop.

What what would have been more helpful initially would have been something like: When I am in gear and increase the throttle, the engine revs but the boat doesn't move, or moves slightly sort of thing.

Oh, and welcome to iboats, your #1 source for boating info and parts. Selling parts keeps this form alive.

 

[OldWilly]

Thanks, when I advance the throttle past idle the motor will start to rev for a second but then the rpm's drop right off. Yesterday I got on plane and and then throttled back to idle then advanced the throttle again but the motor would not rev. So a idled back to the launch and pulled the prop off and with no load the motor will rev. Fuel cap is venting and I replace the fuel lines,filter,plugs the trigger and some other corroded wires. What I am wanting to figure out is if the prop hub is spun would that prevent the motor from reving past idle only under a load.

 

[Outsider]

What I am wanting to figure out is if the prop hub is spun would that prevent the motor from reving past idle only under a load.

No, exactly the opposite, it would rev higher ...

 

[bassman284]

What I am wanting to figure out is if the prop hub is spun would that prevent the motor from reving past idle only under a load.

No, exactly the opposite, it would rev higher ...

Uh yeah. That's what I was going to say. Sounds like there are two different problems here.

 

[Texasmark]

Uh yeah. That's what I was going to say. Sounds like there are two different problems here.

Totally agree on 2 different problems. I didn't see any carb work in your list. May have some crud in there plugging and unplugging your high speed jet(s). I had a somewhat similar problem and just accidentally found the smoking gun. After the Berryman's Chem Tool treatment, I was blowing out the bowl. The high speed jets on these carbs were in the bottom of the bowl. Just by accident I dislodged this little black piece of crud....best guess is a piece of degraded fuel line between the inline filter in the engine and the carbs. Apparently it would move around and be a problem then not then would etc.

Might give them a kit or at least a cleaning and be sure and set your low speed jets screw adjustments which are in the circuit when attempting to get on plane.

 

[OldWilly]

Got it wrapped up, the fuel filter element was torn at the top and the carbs had debri in them restricting the slow and main circuits. Im happy cause the carbs are in great shape so I will clean them out and get a gasket kit.

 

[Texasmark]

Glad there's light at the end of the tunnel.