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I think carb float is malfunctioning

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Gjkelley31

New member
Hi guys, I have a 1974 40 HP Johnson. I fully rebuilt and cleaned the carb before this which fixed the needle valve that wasn't closing causing causing to spit out the carb. Anyways, afterward it still hasn't been starting or if I get it to sputter, it doesn't stay running/idling and always only if the choke is on. I opened the carb back up today and noticed that the new float isn't really lifting all that much when you flip it back and forth. I'm not sure if it's opening the right amount or not. the bowl was filled with gas when I opened it up. Here are some pics to show what I'm talking about. Looks like the tab on the float that keeps it from opening too much is really long. Let me know what you think. I really want to get out on the water atleast once this summer.

https://i.imgur.com/KgYiyPM.jpg (Float on top carb orientation -needle closed position)
https://i.imgur.com/sL9Avtj.jpg (tab looks big)
https://i.imgur.com/Z3IskeD.jpg (float on bottom carb orientation [needle "open" position] where float should hang. Angle looks small, needle doesn't seem to lift)
 
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Float is not adjusted properly,not enough fuel entering bowl if it has to be choked, Is float binding on side of bowl? Any new debris in carb second time around Is there possibly a delivery problem with fuel from fuel line,primer bulb malfunction, obstruction in filters,tank pickup tube,
 
Motor has only like 10 hours on it. Has been sitting in a guys basement for several years. Looks brand new.

Did you look at those pics? When it's upside down the float only hangs down (away from carb) that much. Is there an ideal angle?

Also, are there any passages that I don't know about that would have gunk? Like right angles or something that could messing things up?
 
Ok guys, thanks for talking it through with me! I swapped out the new float that looked wonky and replaced it with the old one ( extremely low hour motor so old float looked new) but kept the new needle and seat. Motor started up after a few pulls making sure the choke was staying choked and now it starts on first pull, one handed. I also tightened the slow speed idle screw packing nut which wasn't fully in all the way and adjusted the needle/screw to 1 1/4 turns. Here's a video of it running. Does that idle sound right? Thanks again!


https://youtu.be/7JFMBsqKyO8
 
Sitting that long?........ Way in back of the float chamber drain screw sits the high speed jet. Carefully clean that jet with a piece of single strand steel wire as solvent just doesn't do a proper job on that item.

**********
(Carburetor Adjustment - Single S/S Adjustable Needle Valve)
(J. Reeves)

Initial setting is: Slow speed = seat gently, then open 1-1/2 turns.

Start engine and set the rpms to where it just stays running. In segments of 1/8 turns, start to turn the S/S needle valve in. Wait a few seconds for the engine to respond. As you turn the valve in, the rpms will increase. Lower the rpms again to where the engine will just stay running.

Eventually you'll hit the point where the engine wants to die out or it will spit back (sounds like a mild backfire). At that point, back out the valve 1/4 turn. Within that 1/4 turn, you'll find the smoothest slow speed setting.

When you have finished the above adjustment, you will have no reason to move them again unless the carburetor fouls/gums up from sitting, in which case you would be required to remove, clean, and rebuild the carburetor anyway.
********************

(Carburetor Float Setting)
(J. Reeves)

With the carburetor body held upside down, the float being viewed from the side, adjust the float so that the free end of the float (the end opposite the hinge pin) is ever so slightly higher (just ever so slightly off level) than the other end. And when viewed from the end, make sure it is not cocked.

Thousands of parts in my remaining stock. Not able to list them all. Let me know what you need and I'll look it up for you. Visit my eBay auction at:
********************
 
joereeves said:
Sitting that long?........ Way in back of the float chamber drain screw sits the high speed jet. Carefully clean that jet with a piece of single strand steel wire as solvent just doesn't do a proper job on that item.

**********
(Carburetor Adjustment - Single S/S Adjustable Needle Valve)
(J. Reeves)

Initial setting is: Slow speed = seat gently, then open 1-1/2 turns.

Start engine and set the rpms to where it just stays running. In segments of 1/8 turns, start to turn the S/S needle valve in. Wait a few seconds for the engine to respond. As you turn the valve in, the rpms will increase. Lower the rpms again to where the engine will just stay running.

Eventually you'll hit the point where the engine wants to die out or it will spit back (sounds like a mild backfire). At that point, back out the valve 1/4 turn. Within that 1/4 turn, you'll find the smoothest slow speed setting.

When you have finished the above adjustment, you will have no reason to move them again unless the carburetor fouls/gums up from sitting, in which case you would be required to remove, clean, and rebuild the carburetor anyway.
********************

(Carburetor Float Setting)
(J. Reeves)

With the carburetor body held upside down, the float being viewed from the side, adjust the float so that the free end of the float (the end opposite the hinge pin) is ever so slightly higher (just ever so slightly off level) than the other end. And when viewed from the end, make sure it is not cocked.

Thousands of parts in my remaining stock. Not able to list them all. Let me know what you need and I'll look it up for you. Visit my eBay auction at:
********************
Click to expand...

thanks! To my knowledge it's been sitting for a lonnng time but was hardly used since leaving the factory. I cleaned the carb pretty thoroughly before this and that high speed jet was very clean before I even did anything to it. It's seems to be running great now.

I'll fine tune the idle just as you have stated. I've come across that guide before and gave it a shot earlier today.
 
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