VAC run rough ( about to give up)

[CONSERVATIONMAN]

What make carb? can you send pics of it disassembled?

Marvel-Schebler TSX-114

 

[JOCCO]

Just a thought if you can come up with another carb and distributor it will rule them out. Also weak valve prings can cause issues, ask me how I know.

 

[CONSERVATIONMAN]

As I mentioned I have put on a carb from a running VAC. No change
The distributor is a "rebuilt" from a case 400 - should be compatible correct?

Anyway, changed the condenser runs somewhat better but still bad ( I can at least keep it running)
Put a spart tester inline with #1 plug (Lisle 20610 Inline Spark Tester,

The tester glows good with each spark for a while then as the engine is dying it glows dimly.

Diffrent coil --- no change
Points New, 0.020 gap, cap, rotor new.
Hot wired it - No change.
Added GND to distributer - zilch

New - different plugs tomorrow

Anything else to check?
Thanks
Wally

 

[Pnettis]

Evening...have you tried a compression test....
And what weight of oil are you running in the engine

 

[JOCCO]

Ssomething is breaking down electrically is my best guess based on your spark tester. Not sure on 400 distributor being same others would know. Check where wire goes into distributor that can be bad. Also look at that if it has a small bolt for rust. I have had lots of trouble with rotor buttons as of late. Simple grab a different one. Compression test will only tell you what inside the cylinder but it's worth doing. Try to get some idea what it should have like 110 lbs beforehand. It will not tell cam or valve spring issues. Based on what you are saying I don't think it's one cylinder messing up it's causing a problem all of them. It would run OK on 3 just with a skip. Few more things weights advance in distributor Messing up, gear or slot where it meshes in, bent shaft, wrong rotor button or not fitting correctly.

 

[olddog]

As I mentioned I have put on a carb from a running VAC. No change
The distributor is a "rebuilt" from a case 400 - should be compatible correct?

Anyway, changed the condenser runs somewhat better but still bad ( I can at least keep it running)
Put a spart tester inline with #1 plug (Lisle 20610 Inline Spark Tester,

The tester glows good with each spark for a while then as the engine is dying it glows dimly.

Diffrent coil --- no change
Points New, 0.020 gap, cap, rotor new.
Hot wired it - No change.
Added GND to distributer - zilch

New - different plugs tomorrow

Anything else to check?
Thanks
Wally

Check the plastic/bakelite insulator where the points circuit passes thru the shell of the distributer.
I had one build up with rust around it, partially grounding the circuit.
Also, just for snits and giggles, temporary (easy) test for distributor wire rotation (CW or CCW) swap #2 and #3 plug wires.

 

[kenbob]

You seemed to have narrowed the problem somewhat by saying a different condenser made it run a little better. Those things aren't too expensive. Maybe you should buy another quality condenser, or swap it out with one from another good running tractor.

 

[CONSERVATIONMAN]

Any part numbers for condensor local at auto pparts store
Cap
rotor

 

[kenbob]

I bought a blue streak condenser the last time out....not sure of part number. Between my brothers and I we had 3 brand new no name condensers fail either soon after starting, and in one case not starting at all. BLue streak is either al111 or al4556p part number. I pulled that from another post. I guess Napa owns echlin and also standard which makes blue streak. According to another post standard is a step down from eschlin, but still better than chinese stuff.

 

[nick831]

Is the distributor back in properly and in time? Did you get the cam back in and timed properly? Just a few other thoughts after reading through everything.

 

[nick831]

Also is valve lash set properly. Nick

 

[CONSERVATIONMAN]

So finally, some progress, whether it's the new blue streak condenser or removing the rust from under the distributer points. It now runs if I use the carb I took off of another running VAC. Now to get my carb fixed. Remember I tried it out on the other VAC and it could not be adjusted, needed to run on the choke.

 

[JOCCO]

Yes watch for rust in distributor, I was going too tell you I have seen where the rotor goes extremely rusted. Watch where the condenser and points hook that there not grounding. Suppose if you have cheap point sets they could be bad. My first thought on the carb assuming marvel tsx is rust dirt and plugged passages.