Help with a Cub! Fuel issues????

[Pap]

I was having kinda the same problem and I found out the valve at the tank was about half way stopped up.
I took it off and apart and cleaned it. Works great now.

[john2189]

If you take the gas line loose from the carb and open the valve at the bottom of the gas tank, how is the gas flow?

[Gary Dotson]

Better yet, remove the plug from the bottom of the carb and check the flow for a full minute. If the flow slows down to a trickle, the problem is up stream. If it continues to flow a good stream, for the whole minute, the problem is in the carb.

[72chevelle]

Thanks for all the replies! I had to take a few days off if it since I was waiting on parts. I actually took the carb all apart before I tried to start it Since it was cruddy. I soaked all the parts in carb cleaner bucket then reassembled. My jets were clean enough I could see light through them but had to say to run a wire through them to clean them so it might make sense the jet is too far restricted. I’ve got a new carb on the way from flea bay to try it. Will send this zenith through my ultrasonic washer and get if better if that fixes it. There are no non-ethanol stations around me do I’m sure having a spare will be required.

[69ranger]

I dont really have any thing to add, as far as resolving the problems with the current carb, except that its likely starving for fuel due to a plugged or partly plugged jet. I mess with a lot of motor cycles, and this is the most common issue that I find.

Also use caution!!!! on the Flea Bay carbs, as the quality is hit or miss. I got two in a row, that were missing the vent hole. They ran only when the choke was shut, and died as soon as it was closed.
It seems this is a known issue, that had been addressed here before, but the nice folks here helped me figure it out. It works pretty decent now, but is a little richer than I want it to be.

When spring gets here and I have time, I am going to re-check the float settings, and see if I can make it better.
I may put the old one back on, if I can get a little help straightening the warped top. Maybe, if I get to attend the N E Oklahoma cub fest.

Good luck with your project.

[ricky racer]

My jets were clean enough I could see light through them but had to say to run a wire through them to clean them so it might make sense the jet is too far restricted.

Just because you can see daylight through the jets doesn't mean they are clean. Only seeing a very sharp, well defined circular orifice tells you the jet is clear. If any portion of the orifice is fuzzy when looking through it, there is still a restriction in the jet.

[72chevelle]

Well Full update! I am an idiot!! I was cleaning the Well Vent jet and the idling jet not the main jet. I pulled that out and cleaned it and boom it ran, but it immediately reved to the moon so I imagine i have some work to do on the linkage for the throttle. The throttle wasnt moving at all so I can only imagine the rod that runs to the carb needs to be shorted Thanks everyone for all the help! One more step forward

[staninlowerAL]

Check the lever at the governor where the spring attaches. Might be frozen up from rust/non-use. This lever (part #11 on the attachment) MUST have free and unrestricted movement. It's also somewhat fragile so handle it carefully.

EDIT: I re-read your earlier posts and concluded that this tractor has not been run in a while. Suggest you check all the throttle linkage for freedom of movement and lube all moving connections. Also adjust the throttle linkage rod (#1) at the connection yoke (#3) per the specs.

[k hutchins]

By all means check your carb to governor linkages for free movement and adjustment, but the over rev problem could be internal in the governor itself. When mine did that years ago, what l eventually found was that inside the governor, the pin that attaches the weights to the drive had worked it's way out far enough that when you spun the drive rod the weights didn't turn on it. Therefore preventing the weights from doing their job in regulating the speed.
Just a possibility as you move forward. Check the external linkages first.

Good luck

[72chevelle]

Well, 1 step forward 2 steps back. attached are a few videos. I went in and put on the new fleabay carb and it performed exactly as expected. It ran for a few seconds with choke on only and them died. It would run with the throttle all the way pulled back but only for a few seconds. So I thought let me check the fuel flow. It flowed right under a quart in a minute not sure if that is sufficient but it sure seems so! Then I look over and the fleabay carb is dumping gas all over my floor so I am guessing the float was sunk or not adjusted. I pulled it off and went back to the zenith. Now when I crank it it revs to the moon and dies. The governor doesn't seem to be attempting to control it at all. I checked and the shaft will move when I touch it. Is it time to pull the governor housing apart? In the first video you can see the governor moving the linkage. so Its not frozen.
https://youtu.be/4UjxQ0wvvkE

https://youtube.com/shorts/ZQTlE8yKKog?feature=share

https://youtube.com/shorts/tp1VORf4efs?feature=share

[Jim Becker]

The governor is clearly working in your first video. It pushes the rod back each time the engine quits. Are you sure the throttle shaft isn't installed in the carburetor bottom side up? I wasn't totally convinced whether the choke was working right either. Does pulling the choke rod back close the choke?

[72chevelle]

The governor is clearly working in your first video. It pushes the rod back each time the engine quits. Are you sure the throttle shaft isn't installed in the carburetor bottom side up? I wasn't totally convinced whether the choke was working right either. Does pulling the choke rod back close the choke?

The choke does work no problem at all. I’m going to try to attach a picture of the Rod and see if you can see if it’s installed properly

[72chevelle]

Well, that photo upload did not work. The eyelet for the linkage is Straight up. It’s almost like the governor is not responding fast enough. If I reach up and work the linkage with my hand I can keep it running just fine. But when I let the governor do it it starts to die and the governor immediately pegs it wide open Instead of easing into it. https://youtube.com/shorts/GB26rM7mdZ8?feature=share

[Jim Becker]

It does appear to respond to you moving the governor link by hand. So evidently it is moving the throttle the right direction.

The governor shouldn't have to push the throttle for it to keep running. It should sit there and idle all day without the governor doing anything. Even if the governor isn't working, you need to solve the idle problem before digging into the governor.

I also notice a rattling sort of sound in the first video. I initially thought it was something in the recording and ignored it. Is it a real noise and if so you know what is causing it?

[Don McCombs]

The eyelet for the linkage is Straight up.

Please explain what you mean by this.