Need help with my cub

R

Rianna

Well-known member
Hey everyone! Sorry I've been mia but Cubbie has been running like a charm up until she didn't. Hubby was cutting grass, neighbor stopped by and he shut her off. When he started her up, he choked/stalled her when putting her in gear. She hasn't started since then. He has gone over all electrical and fuel parts several times and can't find anything wrong. He did find the carburetor was warped so we bought a new one (thanks TM Tractor Parts) and thought that would solve the issue. It didn't, but she does have good fuel flow. He's checked the timing 3 times and it appears to be correct. You can pull the start lever and she'll turn over but never acts like she'll start/fire up. Is there anything he's missing? Please point us in the right direction. I've searched on this board and found a lot of solutions but none have helped. I told him I was going to go to the pros...so here I am asking for help again. lol
 
To start the engine you need fuel, compression and spark at the right time. Since it started previously, and on repeated attempts it would not start, I would have thought it was flooded. Now you have added a new carburetor. I doubt if the issue is compression, but it could be related to fuel or spark. It could also be a vapor lock problem with the fuel cap not venting. I would check to see if you have a good spark at the plugs and then make sure you have the carb float set correctly. If the issue is spark, it could be a bad coil or issues with the ignition system (condenser or points). Hard to believe these could have gone bad instantaneously, but I suppose it is possible.
 
There is good spark at the plugs. We replaced the coil a few years ago when we had issues and he's not in here to make sure I'm correct but I think he said he checked something and it looked like the coil is good. I'll have to ask and correct myself later. If it's the fuel cap not venting, she should start with the cap off? I'll get him to check the carb float as well. He took something off (I think it was manifold related,) and said it had really good suction. We thought maybe the gasket had dry rotted and wasn't sealing correctly. This has us baffled. Thank you so much for your suggestions. Any and all are welcome. We've got to get her up and running again. I'm lost without her:(
 
You may want to pull the intake tube off from the carb (between the carb and air cleaner) and try squirting in a little carb cleaner or starting fluid and see if it pops off with that. If it starts and runs for a second or two, the problem is not an electrical or timing issue, it's fuel related. Give that a try and report back.
 
Thank you for the tip. I don't know if he's tried this one yet. I'll get back to you when he does it. Don't give up on me if it's a while before I reply.
 
ricky racer said:
You may want to pull the intake tube off from the carb (between the carb and air cleaner) and try squirting in a little carb cleaner or starting fluid and see if it pops off with that. If it starts and runs for a second or two, the problem is not an electrical or timing issue, it's fuel related. Give that a try and report back.
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Depending on where your new carb was made it might be worthwhile to make sure that it's made right and functioning correctly. Here's a post from the HOW TO forum about checking it over. JMHO Stan https://farmallcub.com/community/threads/how-to-make-a-chinese-carb-work-correctly.117829/
 
ricky racer said:
You may want to pull the intake tube off from the carb (between the carb and air cleaner) and try squirting in a little carb cleaner or starting fluid and see if it pops off with that. If it starts and runs for a second or two, the problem is not an electrical or timing issue, it's fuel related. Give that a try and report back.
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He did pull the intake tube off and squirted starting fluid in there. It didn't start. It does turn over but won't start.
 
Rianna said:
He did pull the intake tube off and squirted starting fluid in there. It didn't start. It does turn over but won't start.
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So you purchased a Zenith carb? What carb was on the cub when it quit starting? Now that you have verified the fuel intake (spray in the carb) and spark at the plugs, next step would be to check the compression. It should be 85-90 on all cylinders to start but even those numbers will be low on power when running. Have you tried to pull start it? DON'T CONNECT TO THE FRONT AXLE TO PREVENT DAMAGE TO THE FRONT END PARTS!! JMHO Stan
 
Just to try to clear some things up, I reread some of your old posts. So what are you working on? I saw one that referenced a 140 and another old post that says a cub with a magneto. Just trying to sort things out. Tks. Stan
 
If it has spark and isn't hitting on starting fluid, I would check the timing after marking sure the plug wires are in the correct order. Unless it broke a crank or something wild, it wouldn't magically lose all compression, right?
 
Farmall450 said:
If it has spark and isn't hitting on starting fluid, I would check the timing after marking sure the plug wires are in the correct order. Unless it broke a crank or something wild, it wouldn't magically lose all compression, right?
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Reference in the first post was that it was running, shut down and not restarted since then. Couple of thoughts: (1) Carbon buildup on the valves could be preventing good seating and (2) if the valves are at marginal setting, when they get hot the length increases slightly thus making the good seating at the block not very well. That's one of the reasons that the valves need to be readjusted when a tuneup is done, to give the correct spacing between the lifters and the valve stems. Also that's the reason I posed the question about pull starting. If the compression is weak for whatever reason sometimes pull starting will work when crank starting with the starter motor or hand crank will not. JMHO Stan
 
staninlowerAL said:
So you purchased a Zenith carb? What carb was on the cub when it quit starting? Now that you have verified the fuel intake (spray in the carb) and spark at the plugs, next step would be to check the compression. It should be 85-90 on all cylinders to start but even those numbers will be low on power when running. Have you tried to pull start it? DON'T CONNECT TO THE FRONT AXLE TO PREVENT DAMAGE TO THE FRONT END PARTS!! JMHO Stan
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No sir, we did not purchase the Zenith carb. The carb that was on there had the IH stamp on it. Checking the compression is next on the list to try. No, we haven't tried to pull start her yet.
 
staninlowerAL said:
Just to try to clear some things up, I reread some of your old posts. So what are you working on? I saw one that referenced a 140 and another old post that says a cub with a magneto. Just trying to sort things out. Tks. Stan
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We have the Cub. The 140 has been long gone.
 
Farmall450 said:
If it has spark and isn't hitting on starting fluid, I would check the timing after marking sure the plug wires are in the correct order. Unless it broke a crank or something wild, it wouldn't magically lose all compression, right?
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The timing has been checked 3 times and appears to be correct. The plug wires are in order, I'm assuming, since he had been cutting grass for a few hours before this happened. This is the first hiccup she's had in years. We're puzzled.
 
staninlowerAL said:
Reference in the first post was that it was running, shut down and not restarted since then. Couple of thoughts: (1) Carbon buildup on the valves could be preventing good seating and (2) if the valves are at marginal setting, when they get hot the length increases slightly thus making the good seating at the block not very well. That's one of the reasons that the valves need to be readjusted when a tuneup is done, to give the correct spacing between the lifters and the valve stems. Also that's the reason I posed the question about pull starting. If the compression is weak for whatever reason sometimes pull starting will work when crank starting with the starter motor or hand crank will not. JMHO Stan
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Thank you for this explanation. This is something he will check out. Where would you or how do you hook it up to pull start it? We had to pull her backwards from the road to the shed when she decided to croak.
 
Rianna said:
Thank you for this explanation. This is something he will check out. Where would you or how do you hook it up to pull start it? We had to pull her backwards from the road to the shed when she decided to croak.
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Run the chain/cable/rope, etc from the front between the front wheels and connect it to a solid casting part like the drawbar or around the torque tube. The idea is not to put any stress on the front end since the castings there are not very large thus more likely to be damaged by sudden/unusual pressure/stress. My preference is a sturdy rope since it has some "stretch" and less likely to cause damage. Other means are acceptable, just use caution. JMHO Stan
 
This may seem stupid but have you checked the gas tank to make sure it has enough fuel? Been there and done that before myself.
You may want to pop the distributor cap off and verify the point gap and clean the points as well.
 
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