6 HP Engine Dies as Soon as I Close the Choke

[Restorator]

So it's a 64H9E Chrysler 6 HP. 2 Cylinders. I cleaned the carb twice already and that didn't help.

Here's how the problem started:
I was cruising just fine on my little john boat when I hit a big wave head on, which almost gave me a concussion, and the motor died. When I started it back up, which I always have to do with the choke pulled out (butterfly closed), it wouldn't let me take the choke off (open the buttefly). As soon as I give it some air, it dies. The buttefly valve can't even stay half open. The speed is really slow, regardless how much I open the throttle. I've cleaned the carb twice, and checked the spark plugs. They look wet and dark, as if there's some black residue on them. But anyway, I sprayed them with degreaser and plugged them back in and that didn't help any. It doesn't let me open the choke up in neutral or in gear.

So the problem started happening as soon as I hit a big wave, so it must have been caused by a hard vibration to the boat/motor. What could it be, and how do I fix it? Fuel is getting into the carb for sure.

Any help would be greatly appreciated.

 

[jerryjerry05]

Re: 6 HP Engine Dies as Soon as I Close the Choke

It's a 78 maybe a 79??? Or somewhere close.
Start with a compression/spark test.
Then do you have a seperate tank or a built in(on top)some have the tank on top.
Gas in the water??
If using the seperate tank.You need to remove or replace any inline connectors.
Rebuild the fuel pump.
The low speed jet is clogged??

 

[Restorator]

Re: 6 HP Engine Dies as Soon as I Close the Choke

Thanks.
It is a 79 I think.
I thought since it starts right away and can go at a low speed then I don't need to check the compression sparks. How might that still be a factor?

The tank is separate, but I've changed the fuel and that hasn't fixed it. How might the inline connectors play a role in this? I know the fuel gets into the carb for sure because the carb bowl is full when I unscrew it.

I don't know where the low-speed or high-speed jets are on the thing, but I've taken it apart and cleaned it twice to no avail.

Just a reminder that this problem started when the boat hit a hard wave which may have knocked something in the motor to start causing this problem.

Thanks in advance.

 

[roscoe]

Re: 6 HP Engine Dies as Soon as I Close the Choke

I'm guessing that the sudden jarring effect of the big wave, shook up the contents of the bowl.
Normally there should only be fuel there, but there is often sediment or foreign material that settles out.
With the shake up, the dirt was mixed into the fuel and sucked into the carb.

Recheck the carb nozzle and jet..

Here is a parts diagram.


http://www.mercruiserparts.com/Show...55/10.png&inbr=1837&bnbr=50&bdesc=FUEL+SYSTEM

 

[Restorator]

Re: 6 HP Engine Dies as Soon as I Close the Choke

It does seem like the problem is as simple as a clogged carb, but I've already cleaned it twice to no avail. Besides, I don't think the problem started something so simple as a wave shaking up the sediment in the carb and clogging something. It was a massive wave, to the point that something could have just snapped in the motor somewhere.

By the way, that diagram doesn't seem to match my carburetor very well, and it's hard to see. Is there one for my exact motor, so that I could finally locate the low/high speed jets?

 

[jerryjerry05]

Re: 6 HP Engine Dies as Soon as I Close the Choke



The screw#15 that holds the bowl is the bottom jet
#23 is the other jet.
The #23 might have small holes in it.they must be clear.
They must be clear.
Compression/spark just to make sure it's operating right.
I worked on a 120 Force that I had to clean the carb 3 times before it worked right.
Then I never did find what was clogging it.
The passages in the small carbs can be hard to clean.
What is the air screw set at?#27
6 (1979) Mercury Chrysler Outboard 61B9B FUEL SYSTEM Diagram and Parts

 

[Restorator]

Re: 6 HP Engine Dies as Soon as I Close the Choke

Ok, I looked at the diagram again and that's definitely not my carburetor. Screw 15 is just the screw that holds up the bowl. It has holes in it for the gas to leak out, but it is sealed shut when screwed all the way in. I don't recognize #23 at all, it's just not there. The bowl looks totally different on this one. I still have no idea where these jets are. But nevertheless, I've cleaned it all twice and not even the slightest change. I'll get compressed air to blow through it like you said, but I get the feeling that the problem might lie in something more serious.
The air screw (the only adjustable screw on the carburetor) is set at 1.5 turns out, but I've played with it and that hasn't helped any. It's usually set at about 1.5 turns out when the engine worked fine.

The engine is a 1979 Chrysler 6 HP. Model # 69H9E. I'll try to find pictures of the carburetor.

Could the problem be with something physical like something that may have cracked or shifted in the lower unit or something when the big wave hit? It revs up fine in neutral, but dies as soon as I open up the air valve (butterfly). But it doesn't even rev up when I put it in gear. It moves very slowly in gear and only with the air intake fully closed (choke on).

 

[wickware]

Re: 6 HP Engine Dies as Soon as I Close the Choke

Can you choke it to kill it or with your hand over the carb?s throat? If not, it might be sucking air at a gasket connection or Etc. You only have a few carb and combustion chamber connection. Inspect them and spray carb cleaner on any suspicious joints. If the cleaner is sniffed/sucked-in you should see/hear a difference in RPM.

 

[jerryjerry05]

Re: 6 HP Engine Dies as Soon as I Close the Choke

Post pics of your carb and motor.
Pics of the inside too.
On your carb.Look at #23 if you have one and make sure the holes if there are clear.

 

[Restorator]

Re: 6 HP Engine Dies as Soon as I Close the Choke

The choke is all the way on, meaning the buttefly valve is fully closed, and that's the only way it will run. So no, choking doesn't kill it. I haven't tried putting my thumb into it, but I imagine it would only make it better by restricting even more air..lol.

If it's sucking air at a gasket, there must be a lot of air. Don't even know what gasket that could be. Could it be a fuel line? I know I've always had a fuel line that leaked just a tiny bit when I overpumped the tank bulb. Could it have gotten worse with the bump and possible suck even more air now? Or is it too minor to cause such a drastic change?

I'm spraying degreaser, isn't it the same thing? I figured carb cleaner just busts apart any gummed up fuel/oil, which degreaser does amazingly as well. Or am I strictly supposed to use carb cleaner?

I didn't try spraying the degreaser into the throat while it's running for fear that it might explode into my face.

 

[Restorator]

Re: 6 HP Engine Dies as Soon as I Close the Choke

Here are pics of a 3.5HP chrysler engine that has the same carburetor:


I'm not anywhere near the boat now, so I can't take pics of it now, sorry. But I don't remember ever seeing any kind of jet when I take the bowl out.

 

[Restorator]

Re: 6 HP Engine Dies as Soon as I Close the Choke

Here are more pics of the carburetor that I found online:

 

[wickware]

Re: 6 HP Engine Dies as Soon as I Close the Choke

Do you have good blue sparks or have you looked in your ignition sys under the flywheel for clues?? Have you examined Ext linkages to know no linkage has bent or changed??

 

[Restorator]

Re: 6 HP Engine Dies as Soon as I Close the Choke

The ignition system has had a problem where the second cylinder wouldn't kick in right away. After starting it and starting to move, it would try to catch, but wouldn't really kick in until a few minutes into the ride. I'd have to throttle down a little where it seems to try to start up, and then it would finally kick in and I'd throttle up all the way and take off.

But that's a separate problem which I've learned to deal with. This one seems like an obvious fuel delivery issue.
What external linkages might you be referring to? Like the fuel hose all the way from the fuel tank up to the filter and to the carb? The fuel definitely gets into the carb at a good flow, but there might be a tiny air leak along the way, which I don't know how much of an issue that might pose..

 

[Restorator]

Re: 6 HP Engine Dies as Soon as I Close the Choke

No more ideas?