"84 MC 470 Dies when I put it in gear

[a1nowell]

Friends,

I need a little sage advice. My 470 has developed this very irritating problem of dieing when I put it into gear, forward or reverse. I can start the engine right back up but will die when I try to ease it into gear. If I run the throttle up to a high RPM in nuetral and slam it into gear then I can cruise. It has been suggested that it may be the accelerator pump in the carburater (Rochester 2 barrel).



Any thoughts?

 

[Bifflefan]

Re: "84 MC 470 Dies when I put it in gear

When was the last GOOD tune up? Including a carb overhaul.

 

[a1nowell]

Re: "84 MC 470 Dies when I put it in gear

New plugs in May carb rebuilt in February. Rebuild kits do not have new accelerator pumps, so the pump is old.

Thanks,

larry

 

[Bifflefan]

Re: "84 MC 470 Dies when I put it in gear

The acc. pump is just that, it only works when you move the throttle open quickly. When you move it slowly it will bearly do anything.

I think you may have something else wrong, The motor is not running right or it would not die.
Have you checked the timing, compression, plug wires, cap rotor, and points (if you have them)? this is all part of the afore mentioned GOOD tune up.

 

[bigbrownbuku]

Re: "84 MC 470 Dies when I put it in gear

look at the shift plate(the point the cable from the helm joins the cable to the gearbox) when you get someone else to shift gears/engine running, the shift switch should not get stuck up the ramp indic ating a problem with high drag on the drive side, cable or shaft etc.

 

[a1nowell]

Re: "84 MC 470 Dies when I put it in gear

I have been going over everything in the doghouse before tearing into the cable system and discovered a burned wire. It is the purple wire that goes to the automatic choke on the carb. Could this be the cause of the engine dyeing when I put it into gear? Isn't this a resistor wire?

Thanks,

Larry

 

[Bondo]

Re: "84 MC 470 Dies when I put it in gear

It is the purple wire that goes to the automatic choke on the carb. Could this be the cause of the engine dyeing when I put it into gear?

Nope,.. That just means your choke isn't working right....

You need to Replace the Lower Shift Cable...
It's a Classic issue,+ your's are the Classic symptoms.....

 

[Quack Addict]

Re: "84 MC 470 Dies when I put it in gear

You need to Replace the Lower Shift Cable...
It's a Classic issue,+ your's are the Classic symptoms.....

I'm not super familiar with the 470, but doesn't the OP's issue sound like a bum shift interrupt switch?

I had the exact same issue (stall when putting into gear) develop a couple weeks back while several miles out in Lake Michigan - engine would start and idle fine, even rev great in neutral - but it would die as soon as shifting into gear. I ended up disconnecting the wire that goes between the shift interrupt switch and distributor and that allowed us to get in to port without a tow. The boat was a little harder than usual to shift out of forward gear but I had to shut the engine off to get it out of reverse.

For what it's worth, don't force the shifter if you have to bypass the shift interrupt; forcing the shifter will stretch the shift cable... and then you're really up a creek.

 

[Bondo]

Re: "84 MC 470 Dies when I put it in gear

but doesn't the OP's issue sound like a bum shift interrupt switch?

Nope,.. Yourself,+ a1nowell, Both need a New Lower Shift Cable....
The Interupt Switch is workin' Perfectly,.... The motor Stalls...
The Cable is dragging, which causes the switch to stay On,+ Not releasing as it will,...
Once you install a New Lower Shift Cable....

 

[a1nowell]

Re: "84 MC 470 Dies when I put it in gear

Bond-o,
Is the burned wire a resistor wire? Where do you get resistor wire?

Thanks,

Larry

 

[bruceb58]

Re: "84 MC 470 Dies when I put it in gear

Measure the voltage at your coil with the points closed. Should be at around 8 to 9V or so. If the resistor wire is bad it could be a lot lower.

I don't think this is your problem though. I believe its the interrupt switch engaging. Does this do the same thing in your driveway? You can try disconnecting the switch and trying it.

 

[guyaverage]

Re: "84 MC 470 Dies when I put it in gear

Is the burned wire a resistor wire? Where do you get resistor wire?

The purple wire at the choke terminal feeds the choke a full 12v (+) and eventually goes back to your ignition switch. The other purple wire going between the coil (+) and the choke terminal is Merc part number 84-94227A2. It is what feeds resisted ignition switched (+) to the coil.

 

[jcole59946]

Re: "84 MC 470 Dies when I put it in gear

Bond-o is correct. My Merc 470 did the same thing until the shift cables were replaced. Now it shift smoothly into gear and never stalls out.