OT 8N tractor wont start. (Been trying for over a year).

I have been working on this thing off and on for over a year and the thing is still not running. I started into it last year hoping to be able to use it as a plow for my driveway. I still can not start it. To make it what I t hought would be more reliable, I replaced the following: gas tank, spark pl ug wires, spark plugs, distributor (I broke the tang on my old one), coil, points, fuel bowel, etc. I checked the timing twice.

I rebuilt the carb and installed it this weekend. It started for a minute h olding the choke in but then backfired and died and could not restart. (The few times I have gotten it to run in the last year it would run for a minu te then backfire violently and not be able to restart). I bought a new carb from TSC as a last ditch effort yesterday. Still no start. Using an old sp ark plug yesterday grounded to the engine it does fire. If I crank on it lo ng enough it acts like it fires for a split second because the starter dise ngages but never takes off. I can feel suction on the throat of the carb wh en cranking, however, I am not so sure the spark plugs are getting gas. It will not start when spraying starting fluid in the throat of the carb. I do n't think spraying starting fluid in one of the spark plug holes and reinst alling the spark plug made a difference either.

As a last ditch effort, I checked compression with the throttle control wid e open and no choke. Of course the engine was cold as I can not get it star ted. The following were the results I obtained:

1= 85psi 2= almost 90 psi 3= almost 90 psi 4= almost 80 psi

I then added 5w30 (all I had) motor oil into the spark plug holes one at a time. I probably used too much as I poured from a quart container, the spac e was tight, and it was getting dark. The following readings were obtained after the addition of oil:

1= 120 psi 2= 130 psi 3= 105 psi 4= 95 psi

I did notice after doing the wet test, oil was coming out of the carb thro at.

I replaced the intake exhaust gasket last year because it had a leak.

I am just so frustrated and not sure what to do at this point.

Reply to
stryped1
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If you're getting a good spark out of it... and spraying starting fluid into the intake doesn't cause it to fire... and it's pulling air through the engine then it's likely that the spark isn't happening at the right time.

--scott

Reply to
Scott Dorsey

Could it be that your distributor is installed 180 degrees off? BTDT.

Reply to
AMuzi

I used to have one of these on the farm... a long time ago. Does the rotor point at the #1 plug wire on the dist cap when #1 is at TDC _compression_ stroke? Pull the plugs and hold your thumb over the hole to be sure it is a compression and not exhaust stroke.

Does the spark seem strong enough? It takes more under compression.

Is this the 6v positive ground version? Coil wired accordingly?

Reply to
Paul in Houston TX

g is still not running. I started into it last year hoping to be able to us e it as a plow for my driveway. I still can not start it. To make it what I thought would be more reliable, I replaced the following: gas tank, spark plug wires, spark plugs, distributor (I broke the tang on my old one), coil , points, fuel bowel, etc. I checked the timing twice.

holding the choke in but then backfired and died and could not restart. (T he few times I have gotten it to run in the last year it would run for a mi nute then backfire violently and not be able to restart). I bought a new ca rb from TSC as a last ditch effort yesterday. Still no start. Using an old spark plug yesterday grounded to the engine it does fire. If I crank on it long enough it acts like it fires for a split second because the starter di sengages but never takes off. I can feel suction on the throat of the carb when cranking, however, I am not so sure the spark plugs are getting gas. I t will not start when spraying starting fluid in the throat of the carb. I don't think spraying starting fluid in one of the spark plug holes and rein stalling the spark plug made a difference either.

ide open and no choke. Of course the engine was cold as I can not get it st arted. The following were the results I obtained:

a time. I probably used too much as I poured from a quart container, the sp ace was tight, and it was getting dark. The following readings were obtaine d after the addition of oil:

You should find an old mechanic that knows about engines to help you out. I t sounds like a simple problem of ignition timing.

Reply to
dsi1

Others have pointed some of these things out, but you need to check timing, firing order, weak spark (someone mentioned reversed wiring on the primary side of the coil). You also need to set the points dwell, or properly set the gap. Spark testers are cheap, and will tell you if the spark is weak, and to be honest, that's what it really sounds like. Make sure you get the right tester (for points ignition systems).

I guess this is a 6 volt system. Turn the ignition on, and check the voltage at both sides of the coil (with the points closed). One side should read the full 6 volts, and the other should be no more than about .2 V. If the ground side is too high, there is a bad ground, or bad wiring through the distributor to ground. If the power side is too low, there is resistance somewhere in the circuit. (Make sure the battery is fully charged.) And as someone else said, that should be a positive ground system. And again, make sure the wires are not reversed on the coil.

Reply to
Bill Vanek

OK, First thing, check the battery connections. If this is still a 6 volt tractor it is positive ground. Reverse the battery connections and it won't start.

Next double check the plug wire locations to make sure you are in the correct order AND correct rotation. 1-2-4-3 , as you face the dist. the top left is #1 below it is #2, on the right side top is #3 bottom #4

Now pull the cap, wipe it clean, and take a points file and clean the contacts, have seen many NEW points that have a coating that keeps them from firing correctly. Reset the gap and make sure they actually open/close, A worn lobe can cause problems. Replace the condenser and be sure there is no rust/crud in the dist.

Pull the plugs and burn them clean with a torch and check the gap. With the plugs out check for a nice hot spark at all 4 plugs.

_______________________

IF this tractor has been converted to 12 volt Negative ground - Check all the above AND make sure that a second ballast resistor is in line to the coil. When you turn on the ignition switch you should see 2.5 - 3 volts at the coil terminal WITH the points closed.

Now put a bit of gas in each cylinder, install the plugs and it should fire and run a few seconds. If the carb is working it should run longer. Carb wise, make sure you have clean fresh cas, and that you have fuel in the carb, a stuck needle or plugged fuel line can cause a lot of problems.

Reply to
Steve W.

ng is still not running. I started into it last year hoping to be able to u se it as a plow for my driveway. I still can not start it. To make it what I thought would be more reliable, I replaced the following: gas tank, spark plug wires, spark plugs, distributor (I broke the tang on my old one), coi l, points, fuel bowel, etc. I checked the timing twice.

e holding the choke in but then backfired and died and could not restart. ( The few times I have gotten it to run in the last year it would run for a m inute then backfire violently and not be able to restart). I bought a new c arb from TSC as a last ditch effort yesterday. Still no start. Using an old spark plug yesterday grounded to the engine it does fire. If I crank on it long enough it acts like it fires for a split second because the starter d isengages but never takes off. I can feel suction on the throat of the carb when cranking, however, I am not so sure the spark plugs are getting gas. It will not start when spraying starting fluid in the throat of the carb. I don't think spraying starting fluid in one of the spark plug holes and rei nstalling the spark plug made a difference either.

wide open and no choke. Of course the engine was cold as I can not get it s tarted. The following were the results I obtained:

a time. I probably used too much as I poured from a quart container, the s pace was tight, and it was getting dark. The following readings were obtain ed after the addition of oil:

This has been converted to 12 volts. Here is a video last night of the spar k I am getting:

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Reply to
stryped1

snipped-for-privacy@yahoo.com wrote in news: snipped-for-privacy@googlegroups.com:

if its been converted to 12 volts it should not be postive ground any more. probably why you have a weak spark. KB

Reply to
Kevin Bottorff

It is negative ground

Reply to
stryped1

Then you really need to make sure the wires are not reversed on the coil, and that the coil is the right one for the system. Like Steve W. said, if it's still a 6 volt coil, it needs a second resistor in line. I was incorrect earlier when I said the voltage should be 6V at the coil, unless 6V systems do not use a resistor. And if they do use a resistor, there should be a resistor bypass for cranking. And like Steve also said, replace the condenser for the points - and clean the points, and make sure they are set right.

You should start by checking the spark at the coil wire, and the spark should be strong and continuous. If it's not, you need to start first with that repair. And check the voltage at the positive side of the coil while cranking. It should be about double the voltage with the key on, but not cranking. If you have a voltmeter, let us know the voltages you get at both sides of the coil, both while cranking, and with the key on.

BTW, you said you replaced the coil, right? Did you account for the change to 12V, and to negative ground when you picked and installed the coil? And did you watch the points while cranking? Do they open and close consistently? Is the distributor shaft loose in the distributor housing?

Reply to
Bill Vanek

That's not correct. With proper functioning, the spark will be produced briefly with every revolution of the engine. As noted strong, it's a snap, snap, snap... not berzzzzzzz. It sort of reads berzzzzzzzzz.

Reply to
M.A. Stewart

Not at the coil wire. There should be 2 sparks with every revolution. And I didn't mean continuous spark, I meant continuous individual sparking for each cylinder, without any dropouts.

Well yes, as opposed to snap, snap, silence, snap...

Reply to
Bill Vanek

00PS... meye bad... two for four cyl's, tree for sex, four for ate, sex for elve, eight for sexteen.
Reply to
M.A. Stewart

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