1967 20hp chrysler: Running too rich im out of ideas, any advice?

my 1967 chrysler o/b has been running way too rich. When i pull it out in the driveway and hook the water up to it in a barrel to get her started she takes a minute to start (which is somewhat normal since its so old) but the idle is a little choppy and will die out if i dont give it a little gas.

The problem is: when i start to throttle up, the rpm's dont quite follow i have to slowly open the throttle til its WOT. then itll start roaring and sounding like the little beast she is. BUT, there is soo much smoke its ridiculous. Also, the side of the carb is spitting fuel out of the peep hole like a cut artery, this happens almost at any throttle position.

I have already replaced:
-Spark plugs
-Voltage regulator
-ALL fuel Lines
-Fuel pump diaphram
-pulled apart and cleaned the carb
-dropped the lower unit and completely cleaned and relubed.
-replaced the terminal on the Magneto

If anyone has ANY ideas, it would be much appreciated. Ive been running 50:1 mix so i dont think its a problem unless i need to go get fuel with no ethanol and a higher grade 2 cycle oil. Please help! thank you in advance!

Re: 1967 20hp chrysler: Running too rich im out of ideas, any advice?

First do a compression test then a spark test.
Clean the carb again and look at the reeds behind the carb.
Bleeding carb:the float's not set right,the needle/seat worn out.
Somethings clogging the needle.
Install a filter between the carb and pump.Wally World G2/G12 depending on hose size.
Water in the gas?
Fuel recirc system clogged?
The air screw,front top of the carb.The seal(if there is one)gone bad .
The setting wrong.
Start at 1 turn out.Then adjust from there.

Re: 1967 20hp chrysler: Running too rich im out of ideas, any advice?

The float system in the carb is not working for some reason.

Worn needle, float stuck or float not floating for some reason. Something stuck in the needle and seat preventing it from closing.

Try pumping the primer bulb and see if fuel comes out the overflow hole on the side of the carb. If it does this will be the reason your motor is drowning in fuel.

With the carb off and inverted you should not be able to blow air through the fuel line that feeds the carb. You could remove the bowl with the carb still on the motor and lightly lift the float to check as well.

I incorrectly installed the pin that the float swivels on once and had the same problem. Just needed to refit it.

Photo of a worn needle. Some needles have a rubber seal on the top. Not sure whether ethanol fuel effects the rubber.

Re: 1967 20hp chrysler: Running too rich im out of ideas, any advice?

It could be a couple of the things y'all said. First the front set screw I can adjust and it does respond to how the motor idles and it can get to the point to where the side hole isn't spouting fuel and the motor not die. But as I throttle up it still spits out fuel. Aaaand I think the float maybe screwed-I remember taking the carb apart and there was a spring on attached. I'm pretty sure I lost that thing. That could be it.

Re: 1967 20hp chrysler: Running too rich im out of ideas, any advice?

And I did pump the primer to where fuel can come out of the side hole. So the engine is drowning in fuel. How can I fix that?

Re: 1967 20hp chrysler: Running too rich im out of ideas, any advice?

You need to fix the float mechanism on that carb. Do you have the model no of the motor? I'll look up the diagram of your carb tonight and get back to you. See what that spring is you mentioned. On my mobil phone at the moment.

Re: 1967 20hp chrysler: Running too rich im out of ideas, any advice?

Anytime the fuel shoots out the side it's the float/needle.
Is the float brass or plastic?
Pics?

Re: 1967 20hp chrysler: Running too rich im out of ideas, any advice?

Jerry, by the time I had written this you had answered it but I'll put it up anyway. Cheers


I could only find a diagram of a later model carb with a good diagram (1982).

The float mechanism consists of 4 main parts.

The float (#21 ind the diagram)
The Float lever pin(# 15)
The needle and seat (23) Photo attached

When fuel is pumped into the carb it enters through the needle and seat. As the fuel level rises in the carb bowl the float pivots on the lever pin and forces the needle up into the seat. This blocks any further fuel entering the carb until it is used by the motor causing the float to drop allowing more fuel to enter. If the needle is not working properly fuel will keep filling the carb until it exits the carb through the overflow hole in the side of the carb.

Probably the easiest way to check is to take the carb off the motor again and have a good look to see what is happening. Take the bowl off the bottom of the carb and see it the float moves easily up and down on the lever pin. Invert the carb and try to blow air through the fuel intake hose. The weight of the float should exert enough pressure on the needle to stop air getting through. If air gets through, which it probably will, you need to check the needle and seat.

Check to see if the needle can touch the tab on the float. Some needles clip onto the float. It may have come loose. It is possible to put the float on upside down when reassembling it causing it not to touch. If this looks OK you will need to remove the Lever Pin to inspect the needle and seat. The lever pin comes out Knurled end first. With the float off you can now remove the needle. If the taper on the needle has indents (as previous post) it is worn and will need to be replaced. Look down the tube where the needle came out of to check the seat. If there is any dirt clean with carbie cleaner and compressed air. Some seats are press fit and some screw in. If yours is the screw in type check that it is tight as fuel may be leaking past the base of the seat assembly.

Check to see if the float actually floats. Place it in some fuel and check. The foam types can get soggy or the brass or plastic ones can get a hole in them and fill with fuel.

If all looks good replace the needle in the seat, point first and lightly press the needle with your finger. Try the air test again and see if it seals this time. If it doesn’t you need a new needle and seat. If it seals replace the float and float pin and air check again. Hopefully it seals. If all is Ok at this stage you need to check the float level. With the carb inverted the float should be parallel with the body of the carb. You may need to adjust the tab on the float until it sits level.

As far as the extra spring is concerned this carb only has four that I can see. No. 5, 7, 10 & 13. They all look different so should be easy to pick where the one you have should go.

Re: 1967 20hp chrysler: Running too rich im out of ideas, any advice?

I want to say #7 on the diagram is the spring that may be missing. The model number is 20741. I actually have the original owners Manual from the stone age I'll see if there's a diagram on that. I'll pull her apart this weekend and see if I can fix the float. Oh btw it is a plastic black circle float. (almost looks like a throwable life preserver). I do however remember blowing into the fuel line-in when the float was suppose to be stopping flow. And it actually worked. So maybe the float, isn't floating? Ill take pics this weekend.

Re: 1967 20hp chrysler: Running too rich im out of ideas, any advice?

Tinkered around with the Carb today. The spring i had thought got lost is actually still there i put it back in. Sooo its either the float mechanism is broke, or I found another set screw on top of the carb that might adjust the the fuel--Its a set screw on top that looks like #31 or #32 in the diagram TwoFish posted i may have to adjust.

Re: 1967 20hp chrysler: Running too rich im out of ideas, any advice?

http://youtu.be/q5WksJFtJK4


heres a video of the Run Test about a month ago after i just finished putting her back together enough to run.. This was right after i completely serviced the lower unit.. you can tell shes running a little rich, but after a minute with her at WOT itll smoke like crazy. also at the beginning of the video you can tell the voltage regulator has fuel on it, and you can kinda see the fuel spitting out of the overflow hole

Re: 1967 20hp chrysler: Running too rich im out of ideas, any advice?

You will need to sort out the float first. Can’t tell much about how it is running until then.

Parts no 31 & 32 are welsh plugs used to block off machining holes from the manufacturing process. You can not adjust then. The no. 32 will look like a small copper ball and no. 31 will look like a flat metal plate. May be different on your carb as the diagram is of a later model.

No. 9 on the diagram is the idle mixture adjustment screw. Used to set the mixture of fuel/air at idle. Look at the FAQ section on top of the Force - Chrysler thread for Frank’s “Link And Sync” post for setting. Your manual should have a section on it as well. The main jet in the carb is no. 25. This is not adjustable.

If you were missing the spring off of the choke butterfly it could be closing partially and causing it to run rich. At idle it didn’t seem to smoke badly. Sort the float out and see how it goes then.

Re: 1967 20hp chrysler: Running too rich im out of ideas, any advice?

No.9 i have set correctly, she seems to idle alright and only sometimes spouts fuel out of the overflow hole. the spring isnt missing i made sure it was in there. Ill look at that forum and see whats up with the float. thanks for yalls help!

Re: 1967 20hp chrysler: Running too rich im out of ideas, any advice?



heres a few pictures of my carb, i appologize for the quality, im at work and this computer sucks. Is there any way to adjust the float without me dropping the bowl? if not to adjust the float theres just a tab in there i bend to make the float stand parrelel to the ground when the carb bowl is inverted?

Re: 1967 20hp chrysler: Running too rich im out of ideas, any advice?

Yes there is a metal tab on the float. The carb needs to be inverted to set the float so the carb needs to come off unfortunately.



I saw a post by another member “Jiggz” who had a quick way of checking whether the float system is working. Take the carb bowl off and pump the primer bulb to see if fuel flow into the carb. Then hold the float up whilst pumping the primer to see if the needle stops the flow. Seemed to me a good way to do a quick check.

Yes there is a metal tab on the float. The carb needs to be inverted to set the float so unless you can hold the boat upside down the carb needs to come off unfortunately.

I saw a post by another member “Jiggz” who had a quick way of checking whether the float system is working. Take the carb bowl off and pump the primer bulb to see if fuel flow into the carb. Then hold the float up whilst pumping the primer to see if the needle stops the flow. Seemed to me a good way to do a quick check.

In the third photo I can see the screw you mentioned earlier. It is in the same position as the welsh plug in the carb diagram above. I have no idea what it is for. I’d say the screw above the throat of the carb is the idle mixture screw. Hopefully someone will know.

Have you checked to see if the float floats?

Re: 1967 20hp chrysler: Running too rich im out of ideas, any advice?

Take off the bowl. It's a piece of cake, if you can turn a bolt you cant do it. Drain the fuel. hold the carb upside down and blow into where the fuel comes into the carb. It isn't supposed to let anything through, but it probably will. Is the needle even there? You have a total failure of the float/needle system.

Take the carb off, take the float off, and take a pic of it. Take a pic inside the valve area where the needle goes too.

Re: 1967 20hp chrysler: Running too rich im out of ideas, any advice?

I worked on my motor this weekend and I found a few things possibly wrong with it. I took some pictures of it. When I pulled off the bowl the float wasnt even close to set, it would damn near go vertical. I bent the tab to where the carb was inverted and the float was parallel. I blew into the fuel line in and air would come through the carb still it's metal on metal so I don't see how it would stop any fuel. I even hooked the fuel line to the bowl without it being hooked up to the carb and the float worked but would never stop fuel flow. After everything I tried to run the motor cause I did adjust the float. Still really rich and I took a video on YouTube showing the fuel still sporting out of the overflow. Help please! My next step is getting a carb kit and needle and seat. And overhauling the whole carb.

Re: 1967 20hp chrysler: Running too rich im out of ideas, any advice?



http://www.youtube.com/watch?v=MO05zFjI96E&feature=g-upl
that is the video of the run test

Re: 1967 20hp chrysler: Running too rich im out of ideas, any advice?

You were not kidding when you said it was running "rich". Hope you figure it out soon, but by the story about the float, I'd vote for a complete rebuild kit.

Re: 1967 20hp chrysler: Running too rich im out of ideas, any advice?

Yea I've smoked out the neighborhood more than one occasion. I ordered a needle and seat cause actually never found the needle. I just don't want to punt and have to drain the hundreds I've dumped into it.