Stalling Sterndrive

Gregory

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Hello,

New member here from the US. I am a happy owner of a Bayliner 2452 Classic Hardtop Cruiser. It is powered by Mercruiser 5.7L with an Alpha One sterndrive. Everything runs great and seems to be in excellent condition.

Just recently I tried to move the boat under power to a new slip. After warming up the motor and casting off, each time I engaged the drive, the motor died. It would restart and run without hesitation, but again, as soon as I engaged the sterndrive, the motor would die.

Sticking automatic choke??

Thanks
Gregory
Gig Harbor, Washington State
 

BarryH

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I've heard of this before on more than one occasion. As trev has said check the prop is not fouled on anything. Its also worth checking that the tickover is not set too low as this will cause the engine to stall when engaging gear.

I'm sure your engine has an interupt on the ignition circuit when gear is engaged. Its not unknown for for this to be at fault. Check the basic things first tho.
 

davedpc

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The interupter micro switch usually knocks out 2 cylinders to make an easy shift. When the engine is cold this can easily stall the engine if below par. It shouldn't make much dif when hot. The other identical switch may be an isolator to the start motor when in gear. Dave.
 

mercman

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99 percent of the time its a slightly streched shift cable. The cable that comes from the drive up to the shift plate. You can try and adjust these its a matter of undoing the 7/16" nut, remove the split pin and adjust the bronze barrel up or down the thread a couple of turns and try shifting. Failing that boat out of the water, drive off and replace cable with new one.
 

spannerman

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Had the same thing on my Bayliner when it was 4 yrs old, and had it on several other Alpha drives from 3 yrs and older, it could be the shift cable which goes down to the drive is getting stiff, which loads up the micro switch, and causes the motor to cut. If you have the L motor it is designed to momentarily earth the ignition module causing the engine to cut so that you can shift gear while there is no torque in the drive, if the switch is incorrectly adjusted or the cable stiff it shorts the ignition for too long and the motor dies.
You can check it by removing the short cable which goes down behind the exhuast on the SB side and try to pull the cable in and out by hand, if its really heavy or slow to move you need to change it.
Idle speed should be 650 - 700rpm IN GEAR
 

Gregory

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My sincere thanks to everyone. The interupter switch isn't even mentioned in my Clymer Shop Manual, and I have no idea where it's located. This has been suggested to me a couple of times as a possible culprit. Can I do a continuity check on this swtich?

I did not check to see if the prop was fouled, my thinking is, that is my first order of business as there is lots of winter growth on the drive unit at the moment.

The shift cable will be my next area of inspection.

I am not sure what exactly, is a tickover.

Again, many thanks.
Gregory
Gig Harbor, Washington State
USA.
 

spannerman

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The interupter switch is mounted on the inner side of the SB exhaust riser, it will have two control cables connect to a lever, and a microswitch with a roller on a cam connected to the cable mounting plate. Yes you can do a continuity check, there should be an 'open circuit' normally and when you push or pull on the mounting plate for the short cable the roller will ride up the cam one side or the other and you should have continuity thro' the switch, but remember this is designed to work momentarily when you shift OUT of gear, if it closes for too long it will cut the engine.
 
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