Tractor won't start

[Farmville]

I have a 1952 8N, that I've restored. I had it running a year ago and it ran smooth. After about a month I tried starting it again and it would not start. I thought it was a carburetor problem do I bought a new carburetor. That wasn't it. I've replaced the gas tank, gas lines, bowl, carburetor. Points, plugs, distributors cap, condenser, coil, and wiring. It was converted to a 12V when I bought it.

When I first started trying to start it, it was coughing and backfiring which is why I initially thought it was a carburetor problem. But now the engine just turns but with no combustion. Yes, I have spark at each plug and the coil is
hot.

Initially, the engine had 95 PSI on each cylinder so that was a positive.

I have no idea what's going on with this tractor and I feel.like I'm doing the shotgun approach by replacing one thing at a time.

Any insights would be helpful. What am I missing?

Mike

 

[Nyquil Junkie]

Lets see if I have learned enough here to tackle this question...you guys correct me if I make a mistake

I have a 1952 8N, that I've restored. I had it running a year ago and it ran smooth. After about a month I tried starting it again and it would not start.

All things being equal, if it ran good when you parked it, then thats the start point. Something happened in storage. Something degraded, corroded, settled, rusted, leaked or... you know, entropy.

I thought it was a carburetor problem do I bought a new carburetor. That wasn't it.

You don't buy a new carb...you clean and/or rebuild the old one because rebuilt old is better than new. And it ran when parked so it worked fine a month ago. The only thing to go wrong there is water corrosion or rust.

I've replaced the gas tank, gas lines, bowl, carburetor. Points, plugs, distributors cap, condenser, coil, and wiring. It was converted to a 12V when I bought it.

You changed all that just now? How did you know it was all bad? Did you test those parts? What was wrong with the tank lines and bowl (valve?) that couldnt be cleaned?

When I first started trying to start it, it was coughing and backfiring which is why I initially thought it was a carburetor problem. But now the engine just turns but with no combustion. Yes, I have spark at each plug and the coil is
hot.

Did you check to see if you had a free flow out of the carb bowl plug? Actual backfiring could point to a stuck valve or valves. Does it still have good compression? Do another check.

Initially, the engine had 95 PSI on each cylinder so that was a positive.

Good enough. lol

I have no idea what's going on with this tractor and I feel.like I'm doing the shotgun approach by replacing one thing at a time.

You are. You might have swapped a bad old part for an equally bad out of the box new part. You broke the diagnostic chain.

If it has compression, and spark (good blue spark, 1/4 in open air spark) and you have fuel going grom the tank into the carb past the float needle and flowing out the bowl plug at a good clip, then you have all the fixings to start up...Unless its somehow got knocked out of time when you first tried to start it. As I understand, that can happen with a chipped or broke timing gear.

Where would I start first... I'd go to the very beginning and start a new diagnostic chain. Spark, gas, compression, timing. It has to be one of those if it now fails to even try to start, but turns over fast enough.

Don't take for granted all the new parts are working..... new parts often don't. When I rewired mine, the solenoid and the ignition switch were DOA right out of the box.

This post was edited by Nyquil Junkie on 09/03/2023 at 01:26 pm.

 

[Bruce(OR)]

Too many variables to offer a concrete solution.
Sorry'bout that .
95 PSI comp to start with. Was that before the cylinders washed down and comp went to near zero? Or was that
before it back fired collapsing the rings on the pistons and dropping the comp to zero?
Comp NOW is what?
Yeah. I know. too much work to figure it out.
How does you cheat, Right?
Get a second body to crank the engine while you lightly spray ether into the throat.
If it barks, you have a fuel problem.
If it doesn't even whimper, you have a spark problem.
If it pukes, timing might be an issue.

 

[Bruce (VA)]

I feel.like I'm doing the shotgun approach by replacing one thing at a time.

Yes, you are. Stop replacing parts and troubleshoot the problem.

You need to tell us first if its 12v or 6v.

These tractors are amazingly simple machines; they are over 70 years old and were designed to be maintained by the operator.

Some basic troubleshooting skills and a few common tools will get them running. Randomly replacing parts doesnt get you much.

Butyour friends (and maybe your experience) will often get in the way of fixing your tractor. Rarely are guesses like It's the coil helpful. We can make a long list of
possible causes for the tractor not running and start picking our favorite to check out. Or, we can step back and recognize that the trick to fixing these tractors (or trouble
shooting any piece of equipment) is to be systematic about it. You need to isolate the problem system by system, step by step and work from most likely to least likely and
replace parts only when you confirm they are defective. Jumping ahead to 'so-and-so said it could be whatever' or just replacing parts will waste your time and your money.

It takes three things for an engine to run: spark at the right time, compression, & gas/air in the right mixture. Compression is easy; check it with a gauge. But, you don't
lose compression overnight, so if your tractor won't start, or suddenly cuts off, forget about compression for the moment, & concentrate on narrowing the problem to fuel or
spark. If you don't do that, you are going to end up chasing your tail around that tractor & spending a boatload of money to fix what could easily be a loose wire or a clogged
fuel tank vent. I offer this advice from personal experience because I am not a magician. I do not have the magical ability to simply diagnose the problem & go right to the
fix. And I dont like playing guessing games either. So, whenever my tractors stop, I confirm both spark & fuel then go from there.

I might not be capable of telling you why your tractor isn't running, but I sure can tell you how to figure it out for yourself.

Bottom line: as soon as the tractor stops running, not 5 minutes later, check for spark, fuel and battery voltage.

Does the tractor have a spark that will jump 1/4 in open air?*

Will the gas drain out of the carb bowl in a steady stream and fill a pint jar in less than 2 minutes?

What is the EXACT voltage at the battery? ( yes, you need a multimeter for that, not a worthless light)

How do I know this part is defective?

These are the questions you need answered before you attempt any repairs or buy a new part.

*If you dont own a spark checker w/ an adjustable gap ( NOT a light) buy one. In the meantime, an old spark plug w/ the gap opened to at least will work. Ground it to a
rust & paint free spot on the engine turn the key on & look for a spark.

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Automotive
75 Tips

 

[Farmville]

Thank you...

 

[fusion1]

Mike
If this tractor is 6 V
trying putting 12 v to it just while it turns over
see if it trys to start
if your voltage is down with the 6 v
putting 12 to it may help

 

[Eman85]

(quoted from post at 05:50:44 09/09/23) Mike
If this tractor is 6 V
trying putting 12 v to it just while it turns over
see if it trys to start
if your voltage is down with the 6 v
putting 12 to it may help

OP says it was converted to 12V.