1975 Ford 302 Idles/Revs Fine Stalls in N but Stalls in Gear

[Knottymate]

The 302 is hooked up with an OMC in a Slickcraft SS 205. Last fall ran perfect but, always trying to stay ahead, had Plugs, wires, distributor cap, rotor and main fuel line replaced. Always run non ethanol, stabill and sea foam used for winter storage.

Starts fine, idles great, revs up in N but, put in forward gear with little throttle immediately stalls out. Thinking electric choke or vacuum? Could there have been some wire, line knocked loose? Have heard something about some ''switched' in controls
that malfunctions.

 

[Knottymate]

Sorry folks, Idles/Revs fine in N but stalls in Gear Shift with light trottle

 

[Scott Danforth]

replace your lower shift cable

 

[southkogs]

'75 could be an electric shift ...

Does it stall (like it's choking) or does it stop abruptly? What happens if you start it idling and then pull the high idle lever?

 

[Redrig]

Drive locked sounds like .on an electric shift going into gear should be smooth as butter

 

[Scott Danforth]

Disregard post 3, assumed mercruiser.....

 

[kenny nunez]

OMC electric drives spin all the gears.
Have you given some thought to the carberator ? That is where I would look. Holleys tend to experience gasket shrinkage between the metering block and the main body. Get a genuine Holley Marine kit and replace the gaskets and power valve. Auto kits do not have the correct power valve. If the carberator has not been serviced in the last few years it needs it by now.

 

[Redrig]

yeah , Kenny is right , electric shift spins all the gears all the time - my bad

one thing that may cause it to kill the engine is that if the controller is sending 12v to both the F and R shift magnets at the same time . That would kill the engine and probably cause some damage to lower unit as well .

 

[southkogs]

Upper is spinning all of the time ... the lower can lock up, and that's where I was sniffin' around. You can tell that real quick by pulling the drive off.

Kenny knows his stuff, so chase that carb down first.

 

[kenny nunez]

Good point red rig. It has been a long time but I do remember replacing a shift switch that cracked and was the cause of stopping the engine.
Knottymate, try disconnecting the shift wires at the transom. Or unplug the harness from the control box after the engine starts that will also work. You will have to replug to start the engine.
There is also a chance that the shift wire going into the lower unit may be the cause.
All worth checking out to narrow the cause.

 

[Knottymate]

Thanks for all the replies. It shifts so smooth suspect it is an electric shift. Abruptly shuts off. High idle 2000 Rpm no problem. Last fall occasionally it would stagger/stumble on mid throttle acceleration but, 90% of the time ran like a Swiss clock. Another source mentioned something like a switch in the shift control lever.

 

[southkogs]

I think you'd be well served to try disconnecting the shift cables and see what happens. They should be two knife connectors on the port side of the engine toward the back. (If you want to confirm it's an electric shift, post a photo of your drive and your shifter.)

If you disconnect those cables, and you can shift into forward and the engine revolutions climb - then it's likely you have a problem in your lower unit. Make sure you're running water through the system while you try this.

How does your lower unit lube look?