Super A Missing - Looked at Everything I Could Think Of

RTR · Feb 7, 2014

One of our old Super A tractors starts and runs
but not the best.

Stats....original 6 volt with cutout (hi-low
charge bypassed). Runs with no smoke, compression
is 125 on all cyls. New plugs and wires, rebuilt
carb. and adjusted gov. to carb. linkage when
installed, and new battery.

It cranks but turns over a few times before it
starts, I like them to start right off. Once
running it misses badly. I have replaced the
carburetor with a freshly professional rebuilt
unit (that I tried on another tractor before
installing). Slightly helped the choke down when
increased throttle, but still missfiring badly and
now has a surge at idle or half throttle.

What can it be? Distributor worn or maybe it is 1
or 2 teeth off with the governor and out of time??

Will be working on it tomorrow to try and see what
the problem is. Will take a video to show the
issues if needed. Just need some input on what to
look at first and where.

ralph1111 · Feb 7, 2014

Might take a look at valve adjustment , push rods or loose rocker bolts.Sounds as if you got the rest covered.
Ralph

El Toro · Feb 7, 2014

Check for a broken valve spring. Hal

glennster · Feb 7, 2014

pop off the distributor cap and wiggle the rotor side to side. there should be minimun play. if the shaft wiggles, the bushings are bad in the distributor.

RTR · Feb 7, 2014

(quoted from post at 03:47:15 02/08/14) pop off the distributor cap and wiggle the rotor side to side. there should be minimun play. if the shaft wiggles, the bushings are bad in the distributor.

I will try that glenn. When looking at it last night I didn't know how to check distributor bushing wear and noticed that the rotor button would turn back and forth a half inch or so, but I see now that the play would be in the up/down and side/side motion if holding the rotor button. Thanks!

To the others....the compression on all cyls is 125 psi across the board. Would a broken valve spring or any other valve issue allow the compression to be good like this?

glennster · Feb 7, 2014

the back and forth is the centrifugal advance, you should be able to turn the rotor a little and it will kind of snap back. that shows the springs are working.

ken house · Feb 7, 2014

if graphite ignition wires, replace them with copper wires.

might drain carb.

check coil

RTR · Feb 7, 2014

what is the procedure for checking the coil on the tractor without buying a new one to "test" it. ?

Anonymous-0 · Feb 7, 2014

see if the missing is restricted to 1 or more particular cylinders. do so by pulling one plug wire off at a time while engine is running. if so the problem is either distributor cap, plug, wire, or valve most likely. process of elimination can be achieved by swaping plugs and wires back and forth. if the problem moves to a different cylinder than it is a bad plug or wire. (I have had new plugs and wires that were bad.) if problem dont move than it is likely a valve probelm. if the problem is not restricted to particular cylinders then it could be a coil, condenser, or points problem.

old · Feb 7, 2014

Mag or distributor??? Are the new plug wires true wire wires or ones made for a car or truck?? If they are not true copper wire wires you need to replace them again.
Next what does your spark look like?? You need a good blue/white spark at all four plugs that jumps a 1/4 inch gap or more. Also make sure the point gap is correct at all 4 lobes on the distributor. Gap should be 0.020.
Next make sure you have a good steady flow of gas form the carb drain plug. Catch it to look for water/dirt etc.
Also are you sure you have the firing order right??

teddy52food · Feb 7, 2014

I agree with old. Sounds like dirty points & maybe a weak condenser.

David G · Feb 7, 2014

Do what Old suggests, gotta have good spark first.

Duane Rushlo · Feb 7, 2014

if engine is missing on 1 and 2. or 3and4. check manfold gaskets. if they are leaking it will not suck gas to them cyls.check it out by puting a litle oil on intake port of manfold.

RTR · Feb 7, 2014

(quoted from post at 07:32:45 02/08/14) if engine is missing on 1 and 2. or 3and4. check manfold gaskets. if they are leaking it will not suck gas to them cyls.check it out by puting a litle oil on intake port of manfold.

not the manifold gaskets or manifold. changed that out with a spare becuase the original kerosine manifold had a pinhole leak you could feel

504 · Feb 7, 2014

Go with OLD, if the points are worn or out of adjustment, it changes the timing. You always set the points then set the timing.

RTR · Feb 7, 2014

(quoted from post at 07:32:45 02/08/14) if engine is missing on 1 and 2. or 3and4. check manfold gaskets. if they are leaking it will not suck gas to them cyls.check it out by puting a litle oil on intake port of manfold.

not the manifold gaskets or manifold. changed that out with a spare becuase the original kerosine manifold had a pinhole leak you could feel

504 · Feb 7, 2014

BTW make sure your wires are on correct. We bought a M one time(auction) that had new tires, rims, and paint. and missed like crazy.
Paid 500.00 and put the plug wires where they belonged, and sold it the next week for 1500.00

gene bender · Feb 8, 2014

With the engine running and a timing lite go from plug wire to the next should have a steady stream of flashing lite you will probably find the fire is intermitten on one or more of the wires that will show bad wires or a worn dist bush causing missfire.

RTR · Feb 8, 2014

Looked at and Worked on the Super A today. Didn't go as far as pulling the distributor or using a timing light but we thought we could get it out before doing all that. We thought we should check those valves out 1 more time (be a couple months since we checked their adjustment). Couldn't find the feeler gauge but my uncle checked them all by hand and one valve towards the rear of the engine was really tight. We adjusted it out to match the others. Then we started It up and the engine ran "day-night" differently. It wasn't just perfect but it helped big. Then we installed the valve cover and he moved the distributor to adjust te going until it sounded as smooth as it would get. Much better!!!

Waited about 15-20 minutes and started it up to move it. ItwS running poorly again. Not quite as bad as it was but it wasn't right. I want to go back when I have more time and adjust he valves per the manual with a feeler gauge but what do you guys think??

Here is the video. http://youtu.be/HCfNuyIPE8I

Janicholson · Feb 8, 2014

Many tractors go years between valve adjustments (if adjusted correctly) Putting a timing light on each of the plug wires individually first, looking for wheel jumping forward and back (not the timing mark, when it is running at a steady medium speed can show you distributor bushing wear. If the wheel jumps back and forth 1/4" or so as the light stops the wheel, the bushing is probably not good enough to make good timing. Jim

RTR · Feb 9, 2014

Thanks for the tip Mr. Nicholson. Yeah I believe you on that one! I bet alot of them have never had a valve adjustment! I'm going to jump on it on Saturday if I get a chance and try to adjust them out right and use a timing light to see what is going on.

Question: what do you mean by the term "wheel" ? Are you referring to the Flywheel ?

RTR · Feb 9, 2014

Sorry for the non-working link. I just returned home after being out of town for a couple of days and noticed the Video Link wasn't working correctly in my previous post. It should be fixed now.

kopeck · Feb 9, 2014

Boy, sounds like my A.

Sadly I haven't figured it out yet. In my case I think it's a lot of little things adding up to it not running well.

K

RTR · Jun 15, 2014

(quoted from post at 06:38:57 02/10/14) Thanks for the tip Mr. Nicholson. Yeah I believe you on that one! I bet alot of them have never had a valve adjustment! I'm going to jump on it on Saturday if I get a chance and try to adjust them out right and use a timing light to see what is going on.

Question: what do you mean by the term "wheel" ? Are you referring to the Flywheel ?

Wanted to work on the Super A tomorrow. I haven't checked things with a timing light yet, and wanted to ask for some help as in how to do so. Mr. Jim explained what to do, but I really didn't understand what he meant. I pulled a distributor off a parts tractor today and I could always put new parts in it and install it to try....

Super A Missing - Looked at Everything I Could Think Of

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