8N Troubleshooting new no-start issue

[mleroy1989]

Hello,

I'm attempting to troubleshoot my 8N, 6 volt with sidemount distributer that has recently developed a no-start issue. I'll give a quick overview of the issue, followed by recent history of the tractor as well as diagnostic steps I've taken so far.

The tractor is still relatively new to me (4 months) and has had no issues starting or working since I've acquired it. As the weather got colder it took an extra turn or two to fire but still didn't seem to have an issue. Yesterday (warmer than it has been) I attempted to start the tractor. It fired once and stalled then wouldn't restart or fire. The tractor turns over like normal when attempting to start.

After searching the forms here and Google I've attempted the following fixes/diagnosing without resolving the issue:

- Drained fuel from carb with fuel shut off, removed plugs and used lighter to burn off fuel thinking I had flooded the engine.

- Left fuel drain on bottom of carb open with fuel on to ensure steady stream of fuel.

- Battery voltage checked at 6.2.

- Removed spark plug, attached wire and checked spark to block. Spark jumps 1/8 inch, some turns it would jump up to a 1/4 but appeared more yellow than blue most often.

- Removed coil wire and checked spark to block with similar results of spark plug test.

- Voltage at key (toggle switch replacement) showing 6.2 on both sides with key on.

- Disconnected air intake at carb and let tractor rest for a few hours, attempted to restart with no change.

- Drank a beer, then went through each start up step to ensure I wasn't forgetting anything - Fuel on 2 turns, key on, tractor in neutral and clutch depressed - press starter, let turn over for a few seconds then pull and release choke.

- Attempted to check/set timing by rotating flywheel to 4 degrees and rotating distributer while checking for continuity between terminal and ground. I'm not sure the tractor was out of time and my results were very inconclusive so I ended up resetting the distributer to its original position.

- Opened distributer to visualize and parts all look new without corrosion.

- Confirmed firing order from distributer to spark plugs

- Checked wire connections all of which seem to connect well and don't appear corroded or in poor condition.

- Starting fluid in air intake produced no ignition.

- Plugs are currently Champion H10C

At this point I'm left assuming I have a spark issue but I'm not sure where to proceed in terms of diagnosing, adjusting or replacing. My thoughts are to replace the spark plugs with the recommended Autolites, replace coil (unsure how to test, but most forums simply recommended replacement), and/or replace points, condenser, rotor and set timing although they appear newer.

I'm sure I'm missing some critical diagnostic testing. I'd rather not spend the money replacing parts simply hoping they fix the issue but I'll admit I've been down that road before, just not with this tractor!

The tractor has run fine and was started 2-3 times a week for the past 3 months. Occasionally it seemed there was a slight misfire but it never affected the operation of the tractor. And a fun fact - a month after I got the tractor I just happened to notice while doing something else that all 4 spark plugs were loose! Some looser than others, but all less than finger tight! I tightened them but I can't say the tractor even noticed, it ran just the same before I did it!

Hoping someone can point me in the right direction here or link to me another thread where this has been discussed.

Thank you for reading, hopefully I answered the pertinent questions but if you need any more info please ask!

 

[Bruce (VA)]

WOW!

Excellent diagnostics.

You found one problem.

You have a weak spark because you have a weak battery. Put it on a charger. (see tip # 60)

While you are waiting for it to charge, remove the cables and clean the connections on both ends.

Are the cables the correct size? See tip # 41.

Next......leave the timing alone. That's not your problem. But, the points might be. So, check them for pitting & burning & re-set the gap at .025.

Your choice of plugs isn't causing the no-start problem, but they will cause poor performance; see tip # 7.

Post back w/ results or more questions.
75 Tips

 

[mleroy1989]

Bruce, thanks for the reply! I've come across your list of tips a few times and appreciate you taking the time to compile them and especially for responding!

I'll pick up a 6v charger and charge it, I should of checked to see what voltage was considered charged for a 6v battery, I just assumed over 6v was good!

As for the wiring it appears to be a thicker gauge than what I'm used to from working on cars but i wouldn't know what gauge it is. When I get the charger on it I'll check the wiring and see if it's marked. Most of the wiring seems new from the previous owner so there's a decent chance it's readable.

I'll be working on the tractor this Friday so in the meantime I'll see if I can find a write up or video on the points and see what I can find out then!

(quoted from post at 16:26:34 11/29/17) WOW!

Excellent diagnostics.

You found one problem.

You have a weak spark because you have a weak battery. Put it on a charger. (see tip # 60)

While you are waiting for it to charge, remove the cables and clean the connections on both ends.

Are the cables the correct size? See tip # 41.

Next......leave the timing alone. That's not your problem. But, the points might be. So, check them for pitting & burning & re-set the gap at .025.

Your choice of plugs isn't causing the no-start problem, but they will cause poor performance; see tip # 7.

Post back w/ results or more questions.
75 Tips

 

[Bruce (VA)]

A fully charged 6v battery should read 6.35 volts 24 hours after you turn the charger off. It will be higher as soon as you turn it off.

You're going to need a feeler gauge to set the points. It's a blade gauge, not wire like you use for the plugs.

Cables should be as thick as your thumb. 0 or 00 gauge.

OEM was a cable to the starter, braided strap to the chassis.
75 Tips

 

[Steinkamp sales]

Try swapping your old champion plugs with the correct heat range of auto lite plugs. I would bet they are not firing under compression. Good
luck!

 

[JMOR]

(quoted from post at 22:54:23 11/29/17) Try swapping your old champion plugs with the correct heat range of auto lite plugs. I would bet they are not firing under compression. Good
luck!

rands doesn't mean jack! Just what you have read on the 'net'.

 

[allenlane]

Sorry Leroy but I did not see the "Drink a Beer" step in Bruce's list.

Bruce, I'll say it again. That is one awesome list. Can I respectfully suggest a few additions, sorry if I missed them.

Could you add the plug gap, reasonable compression psi range, and reasonable resistance (ohm reading) on the plug wires. These are probably all listed in my future shop manual.

 

[allenlane]

Since I can't edit my post, I think I found a couple...

Plug gap .025, and 90+ psi compression...correct?

 

[mleroy1989]

(quoted from post at 20:27:34 11/29/17) Sorry Leroy but I did not see the "Drink a Beer" step in Bruce's list.

Bruce, I'll say it again. That is one awesome list. Can I respectfully suggest a few additions, sorry if I missed them.

Could you add the plug gap, reasonable compression psi range, and reasonable resistance (ohm reading) on the plug wires. These are probably all listed in my future shop manual.

I didn't see drink a beer in the list of Bruce's tips! But it was number 1 out of 2 on my personal list of tips when troubleshooting malfunctioning equipment!

 

[Bruce (VA)]

No need to add "grab a beer" to the list.......that's simply expected!

Yea, plug gap .025. Minimum acceptable pressure is 90 lbs w/ the lowest pressure reading w/in 75% of the highest reading. Never ohmed a copper plug wire, but it's won't be very high. But, unless you have EI, they do need to be copper.
75 Tips

 

[mleroy1989]

I have a little more messing around to do later but here's what I've got so far!

Got a 6v battery charger and charger battery.

Charged battery and attempted to start without success.

Removed points to inspect and seemed smooth with spindle dimple in the middle that appears to be from manufacturing. One side had some oxidation on the lower portion of the face so I ran 800 grit sandpaper between them to remove and clean

Replaced and verified 0.025 GAP.

Ground cable is 1ga round and the hot cable appears to be same or possible smaller round cable.

Started tractor, fired up after a few turns and run like it had been with a slight misfire. Tractor then alternated between running like normal for me, running better than normal and running slightly tougher than normal. Idle ranked the same and I tired feathering the choke out without indicating a lean/rich issue. The tractor idled like this for approximately 2 minutes then stalled.

I'm running into town for a few errands and when I get back I'll attempt to clean plugs and see report back.

Thanks for the help so far!

 

[mleroy1989]

Sorry for the spelling errors! Can't edit and posting from my phone!

 

[Bruce (VA)]

(quoted from post at 09:41:11 12/01/17) I have a little more messing around to do later but here's what I've got so far!

Got a 6v battery charger and charger battery.

Charged battery and attempted to start without success.

Removed points to inspect and seemed smooth with spindle dimple in the middle that appears to be from manufacturing. One side had some oxidation on the lower portion of the face so I ran 800 grit sandpaper between them to remove and clean

Replaced and verified 0.025 GAP.

Ground cable is 1ga round and the hot cable appears to be same or possible smaller round cable.

Started tractor, fired up after a few turns and run like it had been with a slight misfire. Tractor then alternated between running like normal for me, running better than normal and running slightly tougher than normal. Idle ranked the same and I tired feathering the choke out without indicating a lean/rich issue. The tractor idled like this for approximately 2 minutes then stalled.

I'm running into town for a few errands and when I get back I'll attempt to clean plugs and see report back.

Thanks for the help so far!

As soon as the tractor stops running, not 5 minutes later, check for spark and fuel.

You need to answer 2 questions before you do anything else:

With the bolt in the carb bowl removed and the gas on, will the fuel flow fill a pint jar in less than 2 minutes?

Next, get out your adjustable gap spark checker * , open the gap to 1/4", hook it up, turn the key on and crank the engine. Does the spark jump 1/4"? Post back with the answers.

And do not buy a new part for the tractor until you can answer this question: how do I know the part on the tractor is defective?



* Don't own an adjustable gap spark checker? Buy one! Not a test light! Until then, take an old plug, open the gap 1/4" ground it to the head & look for spark. It’s not the color of the spark that counts; it’s the distance it jumps.

 

[mleroy1989]

I got back and started monkeying around with it before I seen your reply Bruce but I did open up an old plug to 1/4 inch and I do have a spark jumping across it when turning over. Fuel flows from the carb good but I didn't measure it (didn't see your post before coming in.) When I was initially troubleshooting it I drained the carb twice trying to correct what I thought was flooding - the second time I drained it I had forgotten to turn the fuel off and think I drained half the tank with a solid stream of fuel! I'll measure it next time I'm out regardless.

Working on it today I removed the plugs, burned off the residue, cleaned with sandpaper and verified a 0.025 gap. I started the tractor up, it fired up without hesitation and began doing the runs great/runs rough deal. I adjusted the timing slightly by sound and was able to get it running probably as good as it was before this issue began!

I ran the tractor at idle, then took it up and down the driveway letting it run for about 15 minutes and added a few shutdown/restarts in there for good measure. Tractor fires up quicker than before I think and runs the same as before!

Now I'm curious how to resolve the occasional misfire I get. It's a constant, occasional misfire but is most noticeable at low idle or when quickly increasing/decreasing throttle. This misfire doesn't really affect performance for anything that I've done and other than the sound and knowing its not operating at 100% it's not much of an issue. When I cleaned the plugs I did notice that plugs from cylinders 1-3 were dry and cylinder 4 was wet with what appears to be oil residue. Checked tailpipe and noticed thin layer of oil also. To be fair I haven't researched this yet so I'm sure there's answers out there when I get around to looking into it!

Thanks for your help, I'm looking forward to keeping the tractor running and improving it! If it's not running my wife won't be getting to far down our driveway once it snows!

 

[Bruce (VA)]

" I adjusted the timing slightly by sound"

You'll be surprised how far off that can be.

Remove the #1 spark plug. (removing all of them makes the job a bit easier) Ignition off, place your thumb over the #1 spark plug hole and crank slowly until compression is felt. Continue to crank the engine until you see the timing mark, 0* (top dead center) on the flywheel through the timing hole in the right side of the bell housing. Use chalk on the flywheel to exactly align the 4 degree mark with the pointer. Loosen the distributor hold down bolt. Rotate the distributor housing counter clockwise until the points are closed. Put the cap on & double check the plug wires, 1-2-4-3, CCW. Then, remove the primary wire from the side of the distributor (or at the coil, whichever is easier) Put one lead of your VOM (set on resistance) on the stud on the side of the distributor & the other on the block or other good ground. Slowly turn the distributor. The needle will move as the points close & then open. Find the exact spot just as the points open & then tighten down the distributor.

Now check your work (and the dynamic timing) w/ a light.

If it won't idle below 500 rpm (400 is better) don't bother w/ a light.

If it idles ok, make 3 marks w/ chalk or white paint on the flywheel:

4*
10*
17*

Start the engine.

At idle, the light should flash & the marker should line up exactly at 4* if you did the static timing correctly.

If not, loosen the distributor & turn it until the marks line up. It should take very little adjustment.

Once you've got that done, increase the engine speed to 1200 rpms. The light should flash & the marker should line up w/ the 10* mark. Then, increase the rpms to 2000 & look for the marker to align w/ the 17* mark.

Close counts on the advanced timing. A degree or 2 either way is ok. But, no movement or 5* or more off means you have an advance weight problem. You don't adjust the distributor to fix that.

" and cylinder 4 was wet with what appears to be oil residue."

Change # 4 plug with # 1 or 3 and run it for a while & see if # 4 is still oily.

" It's a constant, occasional misfire "

That will drive you nuts. Start w/ the simple stuff/ Pull each wire out of the cap & firmly put it back. Do the same w/ the wires at the plugs.
75 Tips