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Alpha Sterndrive; engine stalls when shifting to neutral !!

M

Mars Lano

New member
When mooring this is a pretty nasty situation. Impact can be inevitable if I can’t restart the engine and reverse fast enough. 😱😱😱
I’ve changed the throttle cables and idle air control valve with new OEM parts but the problem still continues. When the gear is shifted from forward or reverse to neutral, idle speed decreases and eventually the engine stalls. The problem exists even when the engine is warm. The idle speed and all other engine parameters seem normal. The engine is a 5.0 MPI on a Bayliner 2452. I thought someone on this forum might help. Your feedbacks are highly appreciated.
 
You say you changed "throttle cables". Did you change the lower shift cable? Sounds like you need either a new lower shift cable or adjustment or both. Sounds like when in neutral it's activating the shift interrupt switch.
 
Dear Mark, thank you for your feedback. I've also changed the lower shift cable. Actually, it was the only Sierra spare I used. But the throttle cables are changed with original Quicksilver. Could this be a reason ? Could you please also explain ''it's activating the shift interrupt switch'' and how should I adjust it? I heard that this problem is quite typical in Alpha I drives, I don't know if it's true...
 
The alpha 2 has a system whereby when you shift from forward or reverse into neutral it momentarily activates a switch that kills the motor for a split second alowing an easy shift out of gear. Your cable may be out of adjustment so that it is slightly depressing the switch while still in neutral. Search YouTube for Mercruiser Alpha Shift cable adjustment. The video in particular that I'm thinking of is by chrisa660.
 
Mark S. said:
The alpha 2 has a system whereby when you shift from forward or reverse into neutral it momentarily activates a switch that kills the motor for a split second alowing an easy shift out of gear. Your cable may be out of adjustment so that it is slightly depressing the switch while still in neutral. Search YouTube for Mercruiser Alpha Shift cable adjustment. The video in particular that I'm thinking of is by chrisa660.
Click to expand...
Thank you so much Mark, I think you're right! I will check the video. I hope we can fix this issue, it's a nightmare especially when mooring.
 
Mars Lano said:
Dear Mark, thank you for your feedback. I've also changed the lower shift cable. Actually, it was the only Sierra spare I used. But the throttle cables are changed with original Quicksilver. Could this be a reason ? Could you please also explain ''it's activating the shift interrupt switch'' and how should I adjust it? I heard that this problem is quite typical in Alpha I drives, I don't know if it's true...
Click to expand...
I'm not sure I know what you mean above by the statement in red but please know that no adjustment will fix the problem if the cable is bad. You will have to install another cable, preferably OEM.
 
Click on link to a post from here a few down from this one. Instructions on Cable adjustment.

Hard to "find" neutral.

1999 Bayliner Capri 2050 with an Alpha 1 gen. 2 and a 5.0 merc cruiser. It shifts into forward completely and reverse completely but when I'm approaching a dock or the boat trailer, it's hard to find neutral. It seems like I have to go a little past neutral from forward to get it to go into...
www.marineengine.com
 
When the gear is shifted from forward or reverse to neutral, idle speed decreases and eventually the engine stalls. The problem exists even when the engine is warm. The idle speed and

What is the idle speed in neutral?
when the control is pulled all the way back to where the shift takes place ,does the rpm drop ,or does it stall the motor?
 
Bt Doctur said:
When the gear is shifted from forward or reverse to neutral, idle speed decreases and eventually the engine stalls. The problem exists even when the engine is warm. The idle speed and

What is the idle speed in neutral?
when the control is pulled all the way back to where the shift takes place ,does the rpm drop ,or does it stall the motor?
Click to expand...
Hi BT Doctur, I think the idle speed is around 700 in neutral.
Ok, when shifting from forward or reverse to neutral, it takes maximum 3-4 seconds to stall. I think the rpm also drops a bit until that moment.
 
kghost said:
Click on link to a post from here a few down from this one. Instructions on Cable adjustment.

Hard to "find" neutral.

1999 Bayliner Capri 2050 with an Alpha 1 gen. 2 and a 5.0 merc cruiser. It shifts into forward completely and reverse completely but when I'm approaching a dock or the boat trailer, it's hard to find neutral. It seems like I have to go a little past neutral from forward to get it to go into...
www.marineengine.com
Click to expand...
Thank you for the link Kghost, it's a wealth of information down there. This is an awesome forum!
 
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