1980 305 mercruiser inboard stalling at worse possible times

BUA · Jul 15, 2013

I am out of ideas!
Engine idles fine in neutral. When engaging into forward or reverse the engine stalls. Starts right back up.
This is becoming a real problem because coming into docks and moorings and all tight situations the engine stalls at the worse possible time.
I have twin engines and this only happens with the port engine.
Please help if you know the answer.
Thanks

alldodge · Jul 15, 2013

Re: 1980 305 mercruiser inboard stalling at worse possible times

I'm figuring you have an Alpha drive and if this is correct, your shift interuptor is out of adjustment

ktbarrentine · Jul 15, 2013

Re: 1980 305 mercruiser inboard stalling at worse possible times

Lower shift cable replacement time!

Bondo · Jul 15, 2013

Re: 1980 305 mercruiser inboard stalling at worse possible times

ktbarrentine said:
Lower shift cable replacement time!

Ayuh,... That's a Classic symptom of a Failed lower shift cable,... It's Stickin', 'n needs to be replaced,...

DBFLYNN · Jul 16, 2013

Re: 1980 305 mercruiser inboard stalling at worse possible times

I'm having a very similar issue with my sea ray. I have twin 350's , and the starboard motor will be fine for several hours, than all of the sudden when docking or tight maneuvers it stalls. This happens when shifting into forward and reverse. Do you have inboards with transmissions? or out drives? My cables feel fine and I watch the shifting lever on my tranny and it seems to be going into gear smoothly. I'd like to hear what you find.

BUA · Jul 28, 2013

Re: 1980 305 mercruiser inboard stalling at worse possible times

Bond-o said:
Ayuh,... That's a Classic symptom of a Failed lower shift cable,... It's Stickin', 'n needs to be replaced,...

I changed the shift cable and NO LUCK. Still stalling when shifting into forward or reverse after engine is warmed up (doesn't stall until the engine is warmed up).
She starts right up after the stall no problem. I have to bring it up to 1000rpms when I shift to keep from stalling. Not fun when docking in tight windy conditions. Any other ideas?

Bt Doctur · Jul 28, 2013

Re: 1980 305 mercruiser inboard stalling at worse possible times

Is the shift interupter moving when the engine is stalling? If Yes, you have it binding somehow., incorrect routing , installation damage,
shift mechanism corroded/tight,lower unit shift spool/shgift dog issues.

DBFLYNN · Jul 29, 2013

Re: 1980 305 mercruiser inboard stalling at worse possible times

I had a very similar issue and have solved mine. Check your throttle linkage. Mine was pushing too hard towards the closed position. Simple way to check, just after boat acts up, disconnect the linkage and try putting a load on the motor. I was shocked it was such a simple fix. The reason it doesn't act up until its warm is because the choke is on and giving the carb a little extra fuel. As soon as my choke opened all the way and I went to idle position the motor stalled. Your problem sounds just like mine. Good luck.

BUA · Jul 31, 2013

Re: 1980 305 mercruiser inboard stalling at worse possible times

Replaced shift cable.
Bypassed neutral safety switch.
Still has issues.

Idles fine.
Once engine is warmed up to normal running temp she stalls when shifted into gear.
Starts up and idles fine, until shifted into forward or reverse. Once it stalls it continues to stall everytime put in gear. I have to increase RPMS to 1000+ before shifting to keep it running.
reminder....Twin inboards...only one engine has the issue.

Any help will be greatly appreciated, I am out of ideas.
Thanks

alldodge · Aug 1, 2013

Re: 1980 305 mercruiser inboard stalling at worse possible times

So far my understanding is:
It only happens when going into gear not coming out. If you increase the rpm above 1000 just prior it will go into gear without stalling. Once in gear you can throttle back to idle and it will not stall.

If the above is true:
Adjust your idle mixer screws as far out as you can even to the point it is running a bit ruff. Adjust idle speed if necessary to keep it running but not more then about 700. My thought is to get it running on the rich side and see if the problem eases. If it does you can lean it back a bit until it starts acting up again.

BUA · Aug 1, 2013

Re: 1980 305 mercruiser inboard stalling at worse possible times

AllDodge said:
So far my understanding is:
It only happens when going into gear not coming out. If you increase the rpm above 1000 just prior it will go into gear without stalling. Once in gear you can throttle back to idle and it will not stall.

If the above is true:
Adjust your idle mixer screws as far out as you can even to the point it is running a bit ruff. Adjust idle speed if necessary to keep it running but not more then about 700. My thought is to get it running on the rich side and see if the problem eases. If it does you can lean it back a bit until it starts acting up again.

All your assumptions are correct...except
Once it starts the stalling act and the 1000 rpms are required to shift without stalling...I am then unable to throttle it back to idle without it stalling. I need to keep it at the 1000 rpms or it stalls.

alldodge · Aug 1, 2013

Re: 1980 305 mercruiser inboard stalling at worse possible times

BUA said:
All your assumptions are correct...except
Once it starts the stalling act and the 1000 rpms are required to shift without stalling...I am then unable to throttle it back to idle without it stalling. I need to keep it at the 1000 rpms or it stalls.

You can try getting the engine to run a bit richer with backing out the screws a bit, but I'm thinking now you should do a compression test. Don't know if it's a week engine or need the carb rebuilt.

Grub54891 · Aug 1, 2013

Re: 1980 305 mercruiser inboard stalling at worse possible times

You can add some tension to the interrupt switch by slightly stretching the spring behind this plate,you can get these springs new also,take it out,tweak it put it in and try it.

BUA · Aug 1, 2013

Re: 1980 305 mercruiser inboard stalling at worse possible times

grub1grub2 said:
You can add some tension to the interrupt switch by slightly stretching the spring behind this plate,you can get these springs new also,take it out,tweak it put it in and try it.
View attachment 205963

I don't have interrupt switch.
I have a neutral safety switch in an alpha drive inboard.

ktbarrentine · Aug 1, 2013

Re: 1980 305 mercruiser inboard stalling at worse possible times

If you have an alpha drive, you have an interrupt switch

Grub54891 · Aug 1, 2013

Re: 1980 305 mercruiser inboard stalling at worse possible times

ktbarrentine said:
If you have an alpha drive, you have an interrupt switch

^ yup to that.

BUA · Aug 2, 2013

Re: 1980 305 mercruiser inboard stalling at worse possible times

I've been under the impression that my 1980 305 228hp twin inboards has an alpha 1 transmission. Maybe I'm wrong.
I don't have an interrupt switch. I do have a neutral safety switch. I've bypassed the neutral safety switch and I still have the stalling problem. I am going to try running it a little richer today, hopefully that will solve the problem.

r.j.dawg · Aug 2, 2013

Re: 1980 305 mercruiser inboard stalling at worse possible times

I'm betting you have Hurth or Walter transmissions. I agree it sounds like a fuel delivery problem but could also be a damaged damper plate. (missing or broken springs)

ktbarrentine · Aug 2, 2013

Re: 1980 305 mercruiser inboard stalling at worse possible times

BUA said:
I've been under the impression that my 1980 305 228hp twin inboards has an alpha 1 transmission. .

Alpha 1 is an outdrive, not a transmission...
Got pics?

1980 305 mercruiser inboard stalling at worse possible times

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